No functional changes, just s/atomic_t count/int nr_threads/.
With the recent changes this counter has a single user, get_nr_threads()
And, none of its callers need the really accurate number of threads, not
to mention each caller obviously races with fork/exit. It is only used to
report this value to the user-space, except first_tid() uses it to avoid
the unnecessary while_each_thread() loop in the unlikely case.
It is a bit sad we need a word in struct signal_struct for this, perhaps
we can change get_nr_threads() to approximate the number of threads using
signal->live and kill ->nr_threads later.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Trivial, use get_nr_threads() helper to read signal->count which we are
going to change.
Like other callers, proc_sched_show_task() doesn't need the exactly
precise nr_threads.
David said:
: Note that get_nr_threads() isn't completely equivalent (it can return 0
: where proc_sched_show_task() will display a 1). But I don't think this
: should be a problem.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
check_unshare_flags(CLONE_SIGHAND) adds CLONE_THREAD to *flags_ptr if the
task is multithreaded to ensure unshare_thread() will fail.
Not only this is a bit strange way to return the error, this is absolutely
meaningless. If signal->count > 1 then sighand->count must be also > 1,
and unshare_sighand() will fail anyway.
In fact, all CLONE_THREAD/SIGHAND/VM checks inside sys_unshare() do not
look right. Fortunately this code doesn't really work anyway.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move taskstats_tgid_free() from __exit_signal() to free_signal_struct().
This way signal->stats never points to nowhere and we can read ->stats
lockless.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kill the empty thread_group_cputime_free() helper. It was needed to free
the per-cpu data which we no longer have.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanup:
- Add the boolean, group_dead = thread_group_leader(), for clarity.
- Do not test/set sig == NULL to detect the all-dead case, use this
boolean.
- Pass this boolen to __unhash_process() and use it instead of another
thread_group_leader() call which needs ->group_leader.
This can be considered as microoptimization, but hopefully this also
allows us do do other cleanups later.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that task->signal can't go away we can revert the horrible hack added
by ad474caca3 ("fix for
account_group_exec_runtime(), make sure ->signal can't be freed under
rq->lock").
And we can do more cleanups sched_stats.h/posix-cpu-timers.c later.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the last thread exits signal->tty is freed, but the pointer is not
cleared and points to nowhere.
This is OK. Nobody should use signal->tty lockless, and it is no longer
possible to take ->siglock. However this looks wrong even if correct, and
the nice OOPS is better than subtle and hard to find bugs.
Change __exit_signal() to clear signal->tty under ->siglock.
Note: __exit_signal() needs more cleanups. It should not check "sig !=
NULL" to detect the all-dead case and we have the same issues with
signal->stats.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have a lot of problems with accessing task_struct->signal, it can
"disappear" at any moment. Even current can't use its ->signal safely
after exit_notify(). ->siglock helps, but it is not convenient, not
always possible, and sometimes it makes sense to use task->signal even
after this task has already dead.
This patch adds the reference counter, sigcnt, into signal_struct. This
reference is owned by task_struct and it is dropped in
__put_task_struct(). Perhaps it makes sense to export
get/put_signal_struct() later, but currently I don't see the immediate
reason.
Rename __cleanup_signal() to free_signal_struct() and unexport it. With
the previous changes it does nothing except kmem_cache_free().
Change __exit_signal() to not clear/free ->signal, it will be freed when
the last reference to any thread in the thread group goes away.
Note:
- when the last thead exits signal->tty can point to nowhere, see
the next patch.
- with or without this patch signal_struct->count should go away,
or at least it should be "int nr_threads" for fs/proc. This will
be addressed later.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tty_kref_put() has two callsites in copy_process() paths,
1. if copy_process() suceeds it is called before we copy
signal->tty from parent
2. otherwise it is called from __cleanup_signal() under
bad_fork_cleanup_signal: label
In both cases tty_kref_put() is not right and unneeded because we don't
have the balancing tty_kref_get(). Fortunately, this is harmless because
this can only happen without CLONE_THREAD, and in this case signal->tty
must be NULL.
Remove tty_kref_put() from copy_process() and __cleanup_signal(), and
change another caller of __cleanup_signal(), __exit_signal(), to call
tty_kref_put() by hand.
I hope this change makes sense by itself, but it is also needed to make
->signal refcountable.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Preparation to make task->signal immutable, no functional changes.
posix-cpu-timers.c checks task->signal != NULL to ensure this task is
alive and didn't pass __exit_signal(). This is correct but we are going
to change the lifetime rules for ->signal and never reset this pointer.
Change the code to check ->sighand instead, it doesn't matter which
pointer we check under tasklist, they both are cleared simultaneously.
As Roland pointed out, some of these changes are not strictly needed and
probably it makes sense to revert them later, when ->signal will be pinned
to task_struct. But this patch tries to ensure the subsequent changes in
fork/exit can't make any visible impact on posix cpu timers.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change __exit_signal() to check thread_group_leader() instead of
atomic_dec_and_test(&sig->count). This must be equivalent, the group
leader must be released only after all other threads have exited and
passed __exit_signal().
Henceforth sig->count is not actually used, except in fs/proc for
get_nr_threads/etc.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
de_thread() and __exit_signal() use signal_struct->count/notify_count for
synchronization. We can simplify the code and use ->notify_count only.
Instead of comparing these two counters, we can change de_thread() to set
->notify_count = nr_of_sub_threads, then change __exit_signal() to
dec-and-test this counter and notify group_exit_task.
Note that __exit_signal() checks "notify_count > 0" just for symmetry with
exit_notify(), we could just check it is != 0.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change zap_other_threads() to return the number of other sub-threads found
on ->thread_group list.
Other changes are cosmetic:
- change the code to use while_each_thread() helper
- remove the obsolete comment about SIGKILL/SIGSTOP
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
signal_struct->count in its current form must die.
- it has no reasons to be atomic_t
- it looks like a reference counter, but it is not
- otoh, we really need to make task->signal refcountable, just look at
the extremely ugly task_rq_unlock_wait() called from __exit_signals().
- we should change the lifetime rules for task->signal, it should be
pinned to task_struct. We have a lot of code which can be simplified
after that.
- it is not needed! while the code is correct, any usage of this
counter is artificial, except fs/proc uses it correctly to show the
number of threads.
This series removes the usage of sig->count from exit pathes.
This patch:
Now that Veaceslav changed copy_signal() to use zalloc(), exit_notify()
can just check notify_count < 0 to ensure the execing sub-threads needs
the notification from us. No need to do other checks, notify_count != 0
must always mean ->group_exit_task != NULL is waiting for us.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UMH_WAIT_EXEC should report the error if kernel_thread() fails, like
UMH_WAIT_PROC does.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__call_usermodehelper(UMH_NO_WAIT) has 2 problems:
- if kernel_thread() fails, call_usermodehelper_freeinfo()
is not called.
- for unknown reason UMH_NO_WAIT has UMH_WAIT_PROC logic,
we spawn yet another thread which waits until the user
mode application exits.
Change the UMH_NO_WAIT code to use ____call_usermodehelper() instead of
wait_for_helper(), and do call_usermodehelper_freeinfo() unconditionally.
We can rely on CLONE_VFORK, do_fork(CLONE_VFORK) until the child exits or
execs.
With or without this patch UMH_NO_WAIT does not report the error if
kernel_thread() fails, this is correct since the caller doesn't wait for
result.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1. wait_for_helper() calls allow_signal(SIGCHLD) to ensure the child
can't autoreap itself.
However, this means that a spurious SIGCHILD from user-space can
set TIF_SIGPENDING and:
- kernel_thread() or sys_wait4() can fail due to signal_pending()
- worse, wait4() can fail before ____call_usermodehelper() execs
or exits. In this case the caller may kfree(subprocess_info)
while the child still uses this memory.
Change the code to use SIG_DFL instead of magic "(void __user *)2"
set by allow_signal(). This means that SIGCHLD won't be delivered,
yet the child won't autoreap itsefl.
The problem is minor, only root can send a signal to this kthread.
2. If sys_wait4(&ret) fails it doesn't populate "ret", in this case
wait_for_helper() reports a random value from uninitialized var.
With this patch sys_wait4() should never fail, but still it makes
sense to initialize ret = -ECHILD so that the caller can notice
the problem.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
____call_usermodehelper() correctly calls flush_signal_handlers() to set
SIG_DFL, but sigemptyset(->blocked) and recalc_sigpending() are not
needed.
This kthread was forked by workqueue thread, all signals must be unblocked
and ignored, no pending signal is possible.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that nobody ever changes subprocess_info->cred we can kill this member
and related code. ____call_usermodehelper() always runs in the context of
freshly forked kernel thread, it has the proper ->cred copied from its
parent kthread, keventd.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
call_usermodehelper_keys() uses call_usermodehelper_setkeys() to change
subprocess_info->cred in advance. Now that we have info->init() we can
change this code to set tgcred->session_keyring in context of execing
kernel thread.
Note: since currently call_usermodehelper_keys() is never called with
UMH_NO_WAIT, call_usermodehelper_keys()->key_get() and umh_keys_cleanup()
are not really needed, we could rely on install_session_keyring_to_cred()
which does key_get() on success.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The first patch in this series introduced an init function to the
call_usermodehelper api so that processes could be customized by caller.
This patch takes advantage of that fact, by customizing the helper in
do_coredump to create the pipe and set its core limit to one (for our
recusrsion check). This lets us clean up the previous uglyness in the
usermodehelper internals and factor call_usermodehelper out entirely.
While I'm at it, we can also modify the helper setup to look for a core
limit value of 1 rather than zero for our recursion check
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
About 6 months ago, I made a set of changes to how the core-dump-to-a-pipe
feature in the kernel works. We had reports of several races, including
some reports of apps bypassing our recursion check so that a process that
was forked as part of a core_pattern setup could infinitely crash and
refork until the system crashed.
We fixed those by improving our recursion checks. The new check basically
refuses to fork a process if its core limit is zero, which works well.
Unfortunately, I've been getting grief from maintainer of user space
programs that are inserted as the forked process of core_pattern. They
contend that in order for their programs (such as abrt and apport) to
work, all the running processes in a system must have their core limits
set to a non-zero value, to which I say 'yes'. I did this by design, and
think thats the right way to do things.
But I've been asked to ease this burden on user space enough times that I
thought I would take a look at it. The first suggestion was to make the
recursion check fail on a non-zero 'special' number, like one. That way
the core collector process could set its core size ulimit to 1, and enable
the kernel's recursion detection. This isn't a bad idea on the surface,
but I don't like it since its opt-in, in that if a program like abrt or
apport has a bug and fails to set such a core limit, we're left with a
recursively crashing system again.
So I've come up with this. What I've done is modify the
call_usermodehelper api such that an extra parameter is added, a function
pointer which will be called by the user helper task, after it forks, but
before it exec's the required process. This will give the caller the
opportunity to get a call back in the processes context, allowing it to do
whatever it needs to to the process in the kernel prior to exec-ing the
user space code. In the case of do_coredump, this callback is ues to set
the core ulimit of the helper process to 1. This elimnates the opt-in
problem that I had above, as it allows the ulimit for core sizes to be set
to the value of 1, which is what the recursion check looks for in
do_coredump.
This patch:
Create new function call_usermodehelper_fns() and allow it to assign both
an init and cleanup function, as we'll as arbitrary data.
The init function is called from the context of the forked process and
allows for customization of the helper process prior to calling exec. Its
return code gates the continuation of the process, or causes its exit.
Also add an arbitrary data pointer to the subprocess_info struct allowing
for data to be passed from the caller to the new process, and the
subsequent cleanup process
Also, use this patch to cleanup the cleanup function. It currently takes
an argp and envp pointer for freeing, which is ugly. Lets instead just
make the subprocess_info structure public, and pass that to the cleanup
and init routines
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew Tridgell reports that aio_read(SIGEV_SIGNAL) can fail if the
notification from the helper thread races with setresuid(), see
http://samba.org/~tridge/junkcode/aio_uid.c
This happens because check_kill_permission() doesn't permit sending a
signal to the task with the different cred->xids. But there is not any
security reason to check ->cred's when the task sends a signal (private or
group-wide) to its sub-thread. Whatever we do, any thread can bypass all
security checks and send SIGKILL to all threads, or it can block a signal
SIG and do kill(gettid(), SIG) to deliver this signal to another
sub-thread. Not to mention that CLONE_THREAD implies CLONE_VM.
Change check_kill_permission() to avoid the credentials check when the
sender and the target are from the same thread group.
Also, move "cred = current_cred()" down to avoid calling get_current()
twice.
Note: David Howells pointed out we could relax this even more, the
CLONE_SIGHAND (without CLONE_THREAD) case probably does not need
these checks too.
Roland said:
: The glibc (libpthread) that does set*id across threads has
: been in use for a while (2.3.4?), probably in distro's using kernels as old
: or older than any active -stable streams. In the race in question, this
: kernel bug is breaking valid POSIX application expectations.
Reported-by: Andrew Tridgell <tridge@samba.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: <stable@kernel.org> [all kernel versions]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that Mike Frysinger unified the FDPIC ptrace code, we can fix the
unsafe usage of child->mm in ptrace_request(PTRACE_GETFDPIC).
We have the reference to task_struct, and ptrace_check_attach() verified
the tracee is stopped. But nothing can protect from SIGKILL after that,
we must not assume child->mm != NULL.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Mike Frysinger <vapier.adi@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Greg Ungerer <gerg@snapgear.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Blackfin/FRV/SuperH guys all have the same exact FDPIC ptrace code in
their arch handlers (since they were probably copied & pasted). Since
these ptrace interfaces are an arch independent aspect of the FDPIC code,
unify them in the common ptrace code so new FDPIC ports don't need to copy
and paste this fundamental stuff yet again.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some workloads that create a large number of small files tend to assign
too many pages to node 0 (multi-node systems). Part of the reason is that
the rotor (in cpuset_mem_spread_node()) used to assign nodes starts at
node 0 for newly created tasks.
This patch changes the rotor to be initialized to a random node number of
the cpuset.
[akpm@linux-foundation.org: fix layout]
[Lee.Schermerhorn@hp.com: Define stub numa_random() for !NUMA configuration]
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Paul Menage <menage@google.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have observed several workloads running on multi-node systems where
memory is assigned unevenly across the nodes in the system. There are
numerous reasons for this but one is the round-robin rotor in
cpuset_mem_spread_node().
For example, a simple test that writes a multi-page file will allocate
pages on nodes 0 2 4 6 ... Odd nodes are skipped. (Sometimes it
allocates on odd nodes & skips even nodes).
An example is shown below. The program "lfile" writes a file consisting
of 10 pages. The program then mmaps the file & uses get_mempolicy(...,
MPOL_F_NODE) to determine the nodes where the file pages were allocated.
The output is shown below:
# ./lfile
allocated on nodes: 2 4 6 0 1 2 6 0 2
There is a single rotor that is used for allocating both file pages & slab
pages. Writing the file allocates both a data page & a slab page
(buffer_head). This advances the RR rotor 2 nodes for each page
allocated.
A quick confirmation seems to confirm this is the cause of the uneven
allocation:
# echo 0 >/dev/cpuset/memory_spread_slab
# ./lfile
allocated on nodes: 6 7 8 9 0 1 2 3 4 5
This patch introduces a second rotor that is used for slab allocations.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Paul Menage <menage@google.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since we are unable to handle an error returned by
cftype.unregister_event() properly, let's make the callback
void-returning.
mem_cgroup_unregister_event() has been rewritten to be a "never fail"
function. On mem_cgroup_usage_register_event() we save old buffer for
thresholds array and reuse it in mem_cgroup_usage_unregister_event() to
avoid allocation.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hrtimer_get_softirq_time() has it's own xtime lock protection, so it's
safe to use plain __current_kernel_time() and avoid the double seqlock
loop.
Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
LKML-Reference: <20100525214912.GA1934@r2bh72.net.upc.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (63 commits)
drivers/net/usb/asix.c: Fix pointer cast.
be2net: Bug fix to avoid disabling bottom half during firmware upgrade.
proc_dointvec: write a single value
hso: add support for new products
Phonet: fix potential use-after-free in pep_sock_close()
ath9k: remove VEOL support for ad-hoc
ath9k: change beacon allocation to prefer the first beacon slot
sock.h: fix kernel-doc warning
cls_cgroup: Fix build error when built-in
macvlan: do proper cleanup in macvlan_common_newlink() V2
be2net: Bug fix in init code in probe
net/dccp: expansion of error code size
ath9k: Fix rx of mcast/bcast frames in PS mode with auto sleep
wireless: fix sta_info.h kernel-doc warnings
wireless: fix mac80211.h kernel-doc warnings
iwlwifi: testing the wrong variable in iwl_add_bssid_station()
ath9k_htc: rare leak in ath9k_hif_usb_alloc_tx_urbs()
ath9k_htc: dereferencing before check in hif_usb_tx_cb()
rt2x00: Fix rt2800usb TX descriptor writing.
rt2x00: Fix failed SLEEP->AWAKE and AWAKE->SLEEP transitions.
...
This reverts commit 480b02df3a, since
Rafael reports that it causes occasional kernel paging request faults in
load_module().
Dropping the module lock and re-taking it deep in the call-chain is
definitely not the right thing to do. That just turns the mutex from a
lock into a "random non-locking data structure" that doesn't actually
protect what it's supposed to protect.
Requested-and-tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Brandon Philips <brandon@ifup.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The commit 00b7c3395a
"sysctl: refactor integer handling proc code"
modified the behaviour of writing to /proc.
Before the commit, write("1\n") to /proc/sys/kernel/printk succeeded. But
now it returns EINVAL.
This commit supports writing a single value to a multi-valued entry.
Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Reviewed-and-tested-by: WANG Cong <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit f00e047ef (timers: Fix slack calculation for expired timers)
fixed the issue of slack on expired timers only partially. Linus
noticed that jiffies is volatile so it is reloaded twice, which
generates bad code.
But its worse. This can defeat the time_after() check if jiffies are
incremented between time_after() and the slack calculation.
Fix it by reading jiffies into a local variable, which prevents the
compiler from loading it twice. While at it make the > -1 check into
>= 0 which is easier to read.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Currently the trace splice code zeros out the excess bytes in the page before
sending it off to userspace.
This is to make sure userspace is not getting anything it should not be
when reading the pages, because the excess data was never initialized
to zero before writing (for perfomance reasons).
But the splice code has no business in doing this work, it should be
done by the ring buffer. With the latest changes for recording lost
events, the splice code gets it wrong anyway.
Move the zeroing out of excess bytes into the ring buffer code.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The code to store the "lost events" requires knowing the real end
of the page. Since the 'commit' includes the padding at the end of
a page a "real_end" variable was used to keep track of the end not
including the padding.
If events were lost, the reader can place the count of events in
the padded area if there is enough room.
The bug this patch fixes is that when we fill the page we do not
reset the real_end variable, and if the writer had wrapped a few
times, the real_end would be incorrect.
This patch simply resets the real_end if the page was filled.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Remove own implementation of hex_to_bin().
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add global mutex zonelists_mutex to fix the possible race:
CPU0 CPU1 CPU2
(1) zone->present_pages += online_pages;
(2) build_all_zonelists();
(3) alloc_page();
(4) free_page();
(5) build_all_zonelists();
(6) __build_all_zonelists();
(7) zone->pageset = alloc_percpu();
In step (3,4), zone->pageset still points to boot_pageset, so bad
things may happen if 2+ nodes are in this state. Even if only 1 node
is accessing the boot_pageset, (3) may still consume too much memory
to fail the memory allocations in step (7).
Besides, atomic operation ensures alloc_percpu() in step (7) will never fail
since there is a new fresh memory block added in step(6).
[haicheng.li@linux.intel.com: hold zonelists_mutex when build_all_zonelists]
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Andi Kleen <andi.kleen@intel.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For each new populated zone of hotadded node, need to update its pagesets
with dynamically allocated per_cpu_pageset struct for all possible CPUs:
1) Detach zone->pageset from the shared boot_pageset
at end of __build_all_zonelists().
2) Use mutex to protect zone->pageset when it's still
shared in onlined_pages()
Otherwises, multiple zones of different nodes would share same boot strapping
boot_pageset for same CPU, which will finally cause below kernel panic:
------------[ cut here ]------------
kernel BUG at mm/page_alloc.c:1239!
invalid opcode: 0000 [#1] SMP
...
Call Trace:
[<ffffffff811300c1>] __alloc_pages_nodemask+0x131/0x7b0
[<ffffffff81162e67>] alloc_pages_current+0x87/0xd0
[<ffffffff81128407>] __page_cache_alloc+0x67/0x70
[<ffffffff811325f0>] __do_page_cache_readahead+0x120/0x260
[<ffffffff81132751>] ra_submit+0x21/0x30
[<ffffffff811329c6>] ondemand_readahead+0x166/0x2c0
[<ffffffff81132ba0>] page_cache_async_readahead+0x80/0xa0
[<ffffffff8112a0e4>] generic_file_aio_read+0x364/0x670
[<ffffffff81266cfa>] nfs_file_read+0xca/0x130
[<ffffffff8117b20a>] do_sync_read+0xfa/0x140
[<ffffffff8117bf75>] vfs_read+0xb5/0x1a0
[<ffffffff8117c151>] sys_read+0x51/0x80
[<ffffffff8103c032>] system_call_fastpath+0x16/0x1b
RIP [<ffffffff8112ff13>] get_page_from_freelist+0x883/0x900
RSP <ffff88000d1e78a8>
---[ end trace 4bda28328b9990db ]
[akpm@linux-foundation.org: merge fix]
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Andi Kleen <andi.kleen@intel.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable users to online CPUs even if the CPUs belongs to a numa node which
doesn't have onlined local memory.
The zonlists(pg_data_t.node_zonelists[]) of a numa node are created either
in system boot/init period, or at the time of local memory online. For a
numa node without onlined local memory, its zonelists are not initialized
at present. As a result, any memory allocation operations executed by
CPUs within this node will fail. In fact, an out-of-memory error is
triggered when attempt to online CPUs before memory comes to online.
This patch tries to create zonelists for such numa nodes, so that the
memory allocation for this node can be fallback'ed to other nodes.
[akpm@linux-foundation.org: remove unneeded export]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: minskey guo<chaohong.guo@intel.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel applies some heuristics when deciding if memory should be
compacted or reclaimed to satisfy a high-order allocation. One of these
is based on the fragmentation. If the index is below 500, memory will not
be compacted. This choice is arbitrary and not based on data. To help
optimise the system and set a sensible default for this value, this patch
adds a sysctl extfrag_threshold. The kernel will only compact memory if
the fragmentation index is above the extfrag_threshold.
[randy.dunlap@oracle.com: Fix build errors when proc fs is not configured]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a proc file /proc/sys/vm/compact_memory. When an arbitrary value is
written to the file, all zones are compacted. The expected user of such a
trigger is a job scheduler that prepares the system before the target
application runs.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Before applying this patch, cpuset updates task->mems_allowed and
mempolicy by setting all new bits in the nodemask first, and clearing all
old unallowed bits later. But in the way, the allocator may find that
there is no node to alloc memory.
The reason is that cpuset rebinds the task's mempolicy, it cleans the
nodes which the allocater can alloc pages on, for example:
(mpol: mempolicy)
task1 task1's mpol task2
alloc page 1
alloc on node0? NO 1
1 change mems from 1 to 0
1 rebind task1's mpol
0-1 set new bits
0 clear disallowed bits
alloc on node1? NO 0
...
can't alloc page
goto oom
This patch fixes this problem by expanding the nodes range first(set newly
allowed bits) and shrink it lazily(clear newly disallowed bits). So we
use a variable to tell the write-side task that read-side task is reading
nodemask, and the write-side task clears newly disallowed nodes after
read-side task ends the current memory allocation.
[akpm@linux-foundation.org: fix spello]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nick Piggin reported that the allocator may see an empty nodemask when
changing cpuset's mems[1]. It happens only on the kernel that do not do
atomic nodemask_t stores. (MAX_NUMNODES > BITS_PER_LONG)
But I found that there is also a problem on the kernel that can do atomic
nodemask_t stores. The problem is that the allocator can't find a node to
alloc page when changing cpuset's mems though there is a lot of free
memory. The reason is like this:
(mpol: mempolicy)
task1 task1's mpol task2
alloc page 1
alloc on node0? NO 1
1 change mems from 1 to 0
1 rebind task1's mpol
0-1 set new bits
0 clear disallowed bits
alloc on node1? NO 0
...
can't alloc page
goto oom
I can use the attached program reproduce it by the following step:
# mkdir /dev/cpuset
# mount -t cpuset cpuset /dev/cpuset
# mkdir /dev/cpuset/1
# echo `cat /dev/cpuset/cpus` > /dev/cpuset/1/cpus
# echo `cat /dev/cpuset/mems` > /dev/cpuset/1/mems
# echo $$ > /dev/cpuset/1/tasks
# numactl --membind=`cat /dev/cpuset/mems` ./cpuset_mem_hog <nr_tasks> &
<nr_tasks> = max(nr_cpus - 1, 1)
# killall -s SIGUSR1 cpuset_mem_hog
# ./change_mems.sh
several hours later, oom will happen though there is a lot of free memory.
This patchset fixes this problem by expanding the nodes range first(set
newly allowed bits) and shrink it lazily(clear newly disallowed bits). So
we use a variable to tell the write-side task that read-side task is
reading nodemask, and the write-side task clears newly disallowed nodes
after read-side task ends the current memory allocation.
This patch:
In order to fix no node to alloc memory, when we want to update mempolicy
and mems_allowed, we expand the set of nodes first (set all the newly
nodes) and shrink the set of nodes lazily(clean disallowed nodes), But the
mempolicy's rebind functions may breaks the expanding.
So we restructure the mempolicy's rebind functions and split the rebind
work to two steps, just like the update of cpuset's mems: The 1st step:
expand the set of the mempolicy's nodes. The 2nd step: shrink the set of
the mempolicy's nodes. It is used when there is no real lock to protect
the mempolicy in the read-side. Otherwise we can do rebind work at once.
In order to implement it, we define
enum mpol_rebind_step {
MPOL_REBIND_ONCE,
MPOL_REBIND_STEP1,
MPOL_REBIND_STEP2,
MPOL_REBIND_NSTEP,
};
If the mempolicy needn't be updated by two steps, we can pass
MPOL_REBIND_ONCE to the rebind functions. Or we can pass
MPOL_REBIND_STEP1 to do the first step of the rebind work and pass
MPOL_REBIND_STEP2 to do the second step work.
Besides that, it maybe long time between these two step and we have to
release the lock that protects mempolicy and mems_allowed. If we hold the
lock once again, we must check whether the current mempolicy is under the
rebinding (the first step has been done) or not, because the task may
alloc a new mempolicy when we don't hold the lock. So we defined the
following flag to identify it:
#define MPOL_F_REBINDING (1 << 2)
The new functions will be used in the next patch.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch b7e2ecef92 (perf, trace: Optimize tracepoints by removing
IRQ-disable from perf/tracepoint interaction) made the
unfortunate mistake of assuming the world is x86 only, correct
this.
The problem was that perf_fetch_caller_regs() did
local_save_flags() into regs->flags, and I re-used that to
remove another local_save_flags(), forgetting !x86 doesn't have
regs->flags.
Do the reverse, remove the local_save_flags() from
perf_fetch_caller_regs() and let the ftrace site do the
local_save_flags() instead.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: acme@redhat.com
Cc: efault@gmx.de
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1274778175.5882.623.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
commit 3bbb9ec946 (timers: Introduce the concept of timer slack for
legacy timers) does not take the case into account when the timer is
already expired. This broke wireless drivers.
The solution is not to apply slack to already expired timers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
commit 64ce4c2f (time: Clean up warp_clock()) breaks the timezone
update in a very subtle way. To avoid the direct access to timekeeping
internals it adds the timezone delta to the current time with
timespec_add_safe(). This works nicely when the timezone delta is > 0.
If timezone delta is < 0 then the wrap check in timespec_add_safe()
triggers and timespec_add_safe() returns TIME_MAX and screws up
timekeeping completely.
The comment above timespec_add_safe() says:
It's assumed that both values are valid (>= 0)
Add the timezone seconds adjustment directly.
Reported-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* git://git.infradead.org/iommu-2.6:
intel-iommu: Set a more specific taint flag for invalid BIOS DMAR tables
intel-iommu: Combine the BIOS DMAR table warning messages
panic: Add taint flag TAINT_FIRMWARE_WORKAROUND ('I')
panic: Allow warnings to set different taint flags
intel-iommu: intel_iommu_map_range failed at very end of address space
intel-iommu: errors with smaller iommu widths
intel-iommu: Fix boot inside 64bit virtualbox with io-apic disabled
intel-iommu: use physfn to search drhd for VF
intel-iommu: Print out iommu seq_id
intel-iommu: Don't complain that ACPI_DMAR_SCOPE_TYPE_IOAPIC is not supported
intel-iommu: Avoid global flushes with caching mode.
intel-iommu: Use correct domain ID when caching mode is enabled
intel-iommu mistakenly uses offset_pfn when caching mode is enabled
intel-iommu: use for_each_set_bit()
intel-iommu: Fix section mismatch dmar_ir_support() uses dmar_tbl.
* 'modules' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
module: drop the lock while waiting for module to complete initialization.
MODULE_DEVICE_TABLE(isapnp, ...) does nothing
hisax_fcpcipnp: fix broken isapnp device table.
isapnp: move definitions to mod_devicetable.h so file2alias can reach them.
* 'for-2.6.35' of git://git.kernel.dk/linux-2.6-block: (86 commits)
pipe: set lower and upper limit on max pages in the pipe page array
pipe: add support for shrinking and growing pipes
drbd: This is now equivalent to drbd release 8.3.8rc1
drbd: Do not free p_uuid early, this is done in the exit code of the receiver
drbd: Null pointer deref fix to the large "multi bio rewrite"
drbd: Fix: Do not detach, if a bio with a barrier fails
drbd: Ensure to not trigger late-new-UUID creation multiple times
drbd: Do not Oops when C_STANDALONE when uuid gets generated
writeback: fix mixed up arguments to bdi_start_writeback()
writeback: fix problem with !CONFIG_BLOCK compilation
block: improve automatic native capacity unlocking
block: use struct parsed_partitions *state universally in partition check code
block,ide: simplify bdops->set_capacity() to ->unlock_native_capacity()
block: restart partition scan after resizing a device
buffer: make invalidate_bdev() drain all percpu LRU add caches
block: remove all rcu head initializations
writeback: fixups for !dirty_writeback_centisecs
writeback: bdi_writeback_task() must set task state before calling schedule()
writeback: ensure that WB_SYNC_NONE writeback with sb pinned is sync
drivers/block/drbd: Use kzalloc
...
Fix kernel-doc warnings, kernel-doc special characters, and
typos in recent kernel/sysctl.c additions.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Amerigo Wang <amwang@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need at least two to guarantee proper POSIX behaviour, so
never allow a smaller limit than that.
Also expose a /proc/sys/fs/pipe-max-pages sysctl file that allows
root to define a sane upper limit. Make it default to 16 times the
default size, which is 16 pages.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for
growing and shrinking the size of a pipe and adjusts pipe.c and splice.c
(and relay and network splice) usage to work with these larger (or smaller)
pipes.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'dbg-early-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
echi-dbgp: Add kernel debugger support for the usb debug port
earlyprintk,vga,kdb: Fix \b and \r for earlyprintk=vga with kdb
kgdboc: Add ekgdboc for early use of the kernel debugger
x86,early dr regs,kgdb: Allow kernel debugger early dr register access
x86,kgdb: Implement early hardware breakpoint debugging
x86, kgdb, init: Add early and late debug states
x86, kgdb: early trap init for early debug
* 'kdb-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: (25 commits)
kdb,debug_core: Allow the debug core to receive a panic notification
MAINTAINERS: update kgdb, kdb, and debug_core info
debug_core,kdb: Allow the debug core to process a recursive debug entry
printk,kdb: capture printk() when in kdb shell
kgdboc,kdb: Allow kdb to work on a non open console port
kgdb: Add the ability to schedule a breakpoint via a tasklet
mips,kgdb: kdb low level trap catch and stack trace
powerpc,kgdb: Introduce low level trap catching
x86,kgdb: Add low level debug hook
kgdb: remove post_primary_code references
kgdb,docs: Update the kgdb docs to include kdb
kgdboc,keyboard: Keyboard driver for kdb with kgdb
kgdb: gdb "monitor" -> kdb passthrough
sparc,sunzilog: Add console polling support for sunzilog serial driver
sh,sh-sci: Use NO_POLL_CHAR in the SCIF polled console code
kgdb,8250,pl011: Return immediately from console poll
kgdb: core changes to support kdb
kdb: core for kgdb back end (2 of 2)
kdb: core for kgdb back end (1 of 2)
kgdb,blackfin: Add in kgdb_arch_set_pc for blackfin
...
This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The conversion of device->sem to device->mutex resulted in lockdep
warnings. Create a novalidate class for now until the driver folks
come up with separate classes. That way we have at least the basic
mutex debugging coverage.
Add a checkpatch error so the usage is reserved for device->mutex.
[ tglx: checkpatch and compile fix for LOCKDEP=n ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Of the three uses of kref_set in the kernel:
One really should be kref_put as the code is letting go of a
reference,
Two really should be kref_init because the kref is being
initialised.
This suggests that making kref_set available encourages bad code.
So fix the three uses and remove kref_set completely.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (182 commits)
[SCSI] aacraid: add an ifdef'd device delete case instead of taking the device offline
[SCSI] aacraid: prohibit access to array container space
[SCSI] aacraid: add support for handling ATA pass-through commands.
[SCSI] aacraid: expose physical devices for models with newer firmware
[SCSI] aacraid: respond automatically to volumes added by config tool
[SCSI] fcoe: fix fcoe module ref counting
[SCSI] libfcoe: FIP Keep-Alive messages for VPorts are sent with incorrect port_id and wwn
[SCSI] libfcoe: Fix incorrect MAC address clearing
[SCSI] fcoe: fix a circular locking issue with rtnl and sysfs mutex
[SCSI] libfc: Move the port_id into lport
[SCSI] fcoe: move link speed checking into its own routine
[SCSI] libfc: Remove extra pointer check
[SCSI] libfc: Remove unused fc_get_host_port_type
[SCSI] fcoe: fixes wrong error exit in fcoe_create
[SCSI] libfc: set seq_id for incoming sequence
[SCSI] qla2xxx: Updates to ISP82xx support.
[SCSI] qla2xxx: Optionally disable target reset.
[SCSI] qla2xxx: ensure flash operation and host reset via sg_reset are mutually exclusive
[SCSI] qla2xxx: Silence bogus warning by gcc for wrap and did.
[SCSI] qla2xxx: T10 DIF support added.
...
Since we know tracepoints come from kernel context,
avoid conditionals that try and establish that very
fact.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.904944001@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reduce code and data by using the knowledge that for
!PERF_USE_VMALLOC data_order is always 0.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.795019386@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reduce the clutter in perf_output_copy() by keeping
an interator in perf_output_handle.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.742809176@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
RO mmap()s don't update the tail pointer, so
comparing against it for determining the written data
size doesn't really do any good.
Keep track of when we last did a wakeup, and compare
against that.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.684479310@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since we want to ensure buffers only have a single
writer, we must avoid creating one with multiple.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.528215873@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Avoid the swevent hash-table by using per-tracepoint
hlists.
Also, avoid conditionals on the fast path by ordering
with probe unregister so that we should never get on
the callback path without the data being there.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100521090710.473188012@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1674 commits)
qlcnic: adding co maintainer
ixgbe: add support for active DA cables
ixgbe: dcb, do not tag tc_prio_control frames
ixgbe: fix ixgbe_tx_is_paused logic
ixgbe: always enable vlan strip/insert when DCB is enabled
ixgbe: remove some redundant code in setting FCoE FIP filter
ixgbe: fix wrong offset to fc_frame_header in ixgbe_fcoe_ddp
ixgbe: fix header len when unsplit packet overflows to data buffer
ipv6: Never schedule DAD timer on dead address
ipv6: Use POSTDAD state
ipv6: Use state_lock to protect ifa state
ipv6: Replace inet6_ifaddr->dead with state
cxgb4: notify upper drivers if the device is already up when they load
cxgb4: keep interrupts available when the ports are brought down
cxgb4: fix initial addition of MAC address
cnic: Return SPQ credit to bnx2x after ring setup and shutdown.
cnic: Convert cnic_local_flags to atomic ops.
can: Fix SJA1000 command register writes on SMP systems
bridge: fix build for CONFIG_SYSFS disabled
ARCNET: Limit com20020 PCI ID matches for SOHARD cards
...
Fix up various conflicts with pcmcia tree drivers/net/
{pcmcia/3c589_cs.c, wireless/orinoco/orinoco_cs.c and
wireless/orinoco/spectrum_cs.c} and feature removal
(Documentation/feature-removal-schedule.txt).
Also fix a non-content conflict due to pm_qos_requirement getting
renamed in the PM tree (now pm_qos_request) in net/mac80211/scan.c
The kernel debugger can operate well before mm_init(), but the x86
hardware breakpoint code which uses the perf api requires that the
kernel allocators are initialized.
This means the kernel debug core needs to provide an optional arch
specific call back to allow the initialization functions to run after
the kernel has been further initialized.
The kdb shell already had a similar restriction with an early
initialization and late initialization. The kdb_init() was moved into
the debug core's version of the late init which is called
dbg_late_init();
CC: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
It is highly desirable to trap into kdb on panic. The debug core will
attempt to register as the first in line for the panic notifier.
CC: Ingo Molnar <mingo@elte.hu>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Certain calls from the kdb shell will call out to printk(), and any of
these calls should get vectored back to the kdb_printf() so that the
kdb pager and processing can be used, as well as to properly channel
I/O to the polled I/O devices.
CC: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
If kdb is open on a serial port that is not actually a console make
sure to call the poll routines to emit and receive characters.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Martin Hicks <mort@sgi.com>
Some kgdb I/O modules require the ability to create a breakpoint
tasklet, such as kgdboc and external modules such as kgdboe. The
breakpoint tasklet is used as an asynchronous entry point into the
debugger which will have a different function scope than the current
execution path where it might not be safe to have an inline
breakpoint. This is true of some of the kgdb I/O drivers which share
code with kgdb and rest of the kernel users.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The only way the debugger can handle a trap in inside rcu_lock,
notify_die, or atomic_notifier_call_chain without a triple fault is
to have a low level "first opportunity handler" in the int3 exception
handler.
Generally this will be something the vast majority of folks will not
need, but for those who need it, it is added as a kernel .config
option called KGDB_LOW_LEVEL_TRAP.
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: H. Peter Anvin <hpa@zytor.com>
CC: x86@kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Remove all the references to the kgdb_post_primary_code. This
function serves no useful purpose because you can obtain the same
information from the "struct kgdb_state *ks" from with in the
debugger, if for some reason you want the data.
Also remove the unintentional duplicate assignment for ks->ex_vector.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
This patch adds in the kdb PS/2 keyboard driver. This was mostly a
direct port from the original kdb where I cleaned up the code against
checkpatch.pl and added the glue to stitch it into kgdb.
This patch also enables early kdb debug via kgdbwait and the keyboard.
All the access to configure kdb using either a serial console or the
keyboard is done via kgdboc.
If you want to use only the keyboard and want to break in early you
would add to your kernel command arguments:
kgdboc=kbd kgdbwait
If you wanted serial and or the keyboard access you could use:
kgdboc=kbd,ttyS0
You can also configure kgdboc as a kernel module or at run time with
the sysfs where you can activate and deactivate kgdb.
Turn it on:
echo kbd,ttyS0 > /sys/module/kgdboc/parameters/kgdboc
Turn it off:
echo "" > /sys/module/kgdboc/parameters/kgdboc
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
One of the driving forces behind integrating another front end (kdb)
to the debug core is to allow front end commands to be accessible via
gdb's monitor command. It is true that you could write gdb macros to
get certain data, but you may want to just use gdb to access the
commands that are available in the kdb front end.
This patch implements the Rcmd gdb stub packet. In gdb you access
this with the "monitor" command. For instance you could type "monitor
help", "monitor lsmod" or "monitor ps A" etc...
There is no error checking or command restrictions on what you can and
cannot access at this point. Doing something like trying to set
breakpoints with the monitor command is going to cause nothing but
problems. Perhaps in the future only the commands that are actually
known to work with the gdb monitor command will be available.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The design of the kdb shell requires that every device that can
provide input to kdb have a polling routine that exits immediately if
there is no character available. This is required in order to get the
page scrolling mechanism working.
Changing the kernel debugger I/O API to require all polling character
routines to exit immediately if there is no data allows the kernel
debugger to process multiple input channels.
NO_POLL_CHAR will be the return code to the polling routine when ever
there is no character available.
CC: linux-serial@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
These are the minimum changes to the kgdb core in order to enable an
API to connect a new front end (kdb) to the debug core.
This patch introduces the dbg_kdb_mode variable controls where the
user level I/O is routed. It will be routed to the gdbstub (kgdb) or
to the kdb front end which is a simple shell available over the kgdboc
connection.
You can switch back and forth between kdb or the gdb stub mode of
operation dynamically. From gdb stub mode you can blindly type
"$3#33", or from the kdb mode you can enter "kgdb" to switch to the
gdb stub.
The logic in the debug core depends on kdb to look for the typical gdb
connection sequences and return immediately with KGDB_PASS_EVENT if a
gdb serial command sequence is detected. That should allow a
reasonably seamless transition between kdb -> gdb without leaving the
kernel exception state. The two gdb serial queries that kdb is
responsible for detecting are the "?" and "qSupported" packets.
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Martin Hicks <mort@sgi.com>
This patch contains the hooks and instrumentation into kernel which
live outside the kernel/debug directory, which the kdb core
will call to run commands like lsmod, dmesg, bt etc...
CC: linux-arch@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Martin Hicks <mort@sgi.com>
This patch contains only the kdb core. Because the change set was
large, it was split. The next patch in the series includes the
instrumentation into the core kernel which are mainly helper functions
for kdb.
This work is directly derived from kdb v4.4 found at:
ftp://oss.sgi.com/projects/kdb/download/v4.4/
The kdb internals have been re-organized to make them mostly platform
independent and to connect everything to the debug core which is used by
gdbstub (which has long been known as kgdb).
The original version of kdb was 58,000 lines worth of changes to
support x86. From that implementation only the kdb shell, and basic
commands for memory access, runcontrol, lsmod, and dmesg where carried
forward.
This is a generic implementation which aims to cover all the current
architectures using the kgdb core: ppc, arm, x86, mips, sparc, sh and
blackfin. More archictectures can be added by implementing the
architecture specific kgdb functions.
[mort@sgi.com: Compile fix with hugepages enabled]
[mort@sgi.com: Clean breakpoint code renaming kdba_ -> kdb_]
[mort@sgi.com: fix new line after printing registers]
[mort@sgi.com: Remove the concept of global vs. local breakpoints]
[mort@sgi.com: Rework kdb_si_swapinfo to use more generic name]
[mort@sgi.com: fix the information dump macros, remove 'arch' from the names]
[sfr@canb.auug.org.au: include fixup to include linux/slab.h]
CC: linux-arch@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Martin Hicks <mort@sgi.com>
Split the former kernel/kgdb.c into debug_core.c which contains the
kernel debugger exception logic and to the gdbstub.c which contains
the logic for allowing gdb to talk to the debug core.
This also created a private include file called debug_core.h which
contains all the definitions to glue the debug_core to any other
debugger connections.
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Move kgdb.c in preparation to separate the gdbstub from the debug
core and exception handling.
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
New wait_event_interruptible{,_exclusive}_locked{,_irq} macros added.
They work just like versions without _locked* suffix but require the
wait queue's lock to be held. Also __wake_up_locked() is now exported
as to pair it with the above macros.
The use case of this new facility is when one uses wait queue's lock
to protect a data structure. This may be advantageous if the
structure needs to be protected by a spinlock anyway. In particular,
with additional spinlock the following code has to be used to wait
for a condition:
spin_lock(&data.lock);
...
for (ret = 0; !ret && !(condition); ) {
spin_unlock(&data.lock);
ret = wait_event_interruptible(data.wqh, (condition));
spin_lock(&data.lock);
}
...
spin_unlock(&data.lock);
This looks bizarre plus wait_event_interruptible() locks the wait
queue's lock anyway so there is a unlock+lock sequence where it could
be avoided.
To avoid those problems and benefit from wait queue's lock, a code
similar to the following should be used:
/* Waiting */
spin_lock(&data.wqh.lock);
...
ret = wait_event_interruptible_locked(data.wqh, (condition));
...
spin_unlock(&data.wqh.lock);
/* Waiting exclusively */
spin_lock(&data.whq.lock);
...
ret = wait_event_interruptible_exclusive_locked(data.whq, (condition));
...
spin_unlock(&data.whq.lock);
/* Waking up */
spin_lock(&data.wqh.lock);
...
wake_up_locked(&data.wqh);
...
spin_unlock(&data.wqh.lock);
When spin_lock_irq() is used matching versions of macros need to be
used (*_locked_irq()).
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A writer that gets a reference to the buffer handle disables
preemption. When we put that reference, we check if we are
the outer most writer and if not, we simply return and defer
the head update to the outer most writer. The problem here
is that preemption is only reenabled by the outer most, that
produces preemption count imbalance for every nested writer
that exit.
So just don't forget to always re-enable preemption when we
put the buffer reference, whoever we are.
Fixes lots of sleeping in atomic warnings, visible with lock
events recording.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Robert Richter <robert.richter@amd.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (44 commits)
vlynq: make whole Kconfig-menu dependant on architecture
add descriptive comment for TIF_MEMDIE task flag declaration.
EEPROM: max6875: Header file cleanup
EEPROM: 93cx6: Header file cleanup
EEPROM: Header file cleanup
agp: use NULL instead of 0 when pointer is needed
rtc-v3020: make bitfield unsigned
PCI: make bitfield unsigned
jbd2: use NULL instead of 0 when pointer is needed
cciss: fix shadows sparse warning
doc: inode uses a mutex instead of a semaphore.
uml: i386: Avoid redefinition of NR_syscalls
fix "seperate" typos in comments
cocbalt_lcdfb: correct sections
doc: Change urls for sparse
Powerpc: wii: Fix typo in comment
i2o: cleanup some exit paths
Documentation/: it's -> its where appropriate
UML: Fix compiler warning due to missing task_struct declaration
UML: add kernel.h include to signal.c
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: change cancel_work_sync() to clear work->data
workqueue: warn about flush_scheduled_work()
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (61 commits)
KEYS: Return more accurate error codes
LSM: Add __init to fixup function.
TOMOYO: Add pathname grouping support.
ima: remove ACPI dependency
TPM: ACPI/PNP dependency removal
security/selinux/ss: Use kstrdup
TOMOYO: Use stack memory for pending entry.
Revert "ima: remove ACPI dependency"
Revert "TPM: ACPI/PNP dependency removal"
KEYS: Do preallocation for __key_link()
TOMOYO: Use mutex_lock_interruptible.
KEYS: Better handling of errors from construct_alloc_key()
KEYS: keyring_serialise_link_sem is only needed for keyring->keyring links
TOMOYO: Use GFP_NOFS rather than GFP_KERNEL.
ima: remove ACPI dependency
TPM: ACPI/PNP dependency removal
selinux: generalize disabling of execmem for plt-in-heap archs
LSM Audit: rename LSM_AUDIT_NO_AUDIT to LSM_AUDIT_DATA_NONE
CRED: Holding a spinlock does not imply the holding of RCU read lock
SMACK: Don't #include Ext2 headers
...
The software events hlist doesn't fully comply with the new
rcu checks api.
We need to consider three different sides that access the hlist:
- the hlist allocation/release side. This side happens when an
events is created or released, accesses to the hlist are
serialized under the cpuctx mutex.
- the events insertion/removal in the hlist. This side is always
serialized against the above one. The hlist is always present
during such operations. This side happens when a software event
is scheduled in/out. The serialization that ensures the software
event is really attached to the context is made under the
ctx->lock.
- events triggering. This is the read side, it can happen
concurrently with any update side.
This patch deals with them one by one and anticipates with the
separate rcu mem space patches in preparation.
This patch fixes various annoying rcu warnings.
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
clocksource: Add clocksource_register_hz/khz interface
posix-cpu-timers: Optimize run_posix_cpu_timers()
time: Remove xtime_cache
mqueue: Convert message queue timeout to use hrtimers
hrtimers: Provide schedule_hrtimeout for CLOCK_REALTIME
timers: Introduce the concept of timer slack for legacy timers
ntp: Remove tickadj
ntp: Make time_adjust static
time: Add xtime, wall_to_monotonic to feature-removal-schedule
timer: Try to survive timer callback preempt_count leak
timer: Split out timer function call
timer: Print function name for timer callbacks modifying preemption count
time: Clean up warp_clock()
cpu-timers: Avoid iterating over all threads in fastpath_timer_check()
cpu-timers: Change SIGEV_NONE timer implementation
cpu-timers: Return correct previous timer reload value
cpu-timers: Cleanup arm_timer()
cpu-timers: Simplify RLIMIT_CPU handling
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
genirq: Clear CPU mask in affinity_hint when none is provided
genirq: Add CPU mask affinity hint
genirq: Remove IRQF_DISABLED from core code
genirq: Run irq handlers with interrupts disabled
genirq: Introduce request_any_context_irq()
genirq: Expose irq_desc->node in proc/irq
Fixed up trivial conflicts in Documentation/feature-removal-schedule.txt
Commit a45185d2d "cpumask: convert kernel/compat.c" broke libnuma, which
abuses sched_getaffinity to find out NR_CPUS in order to parse
/sys/devices/system/node/node*/cpumap.
On NUMA systems with less than 32 possibly CPUs, the current
compat_sys_sched_getaffinity now returns '4' instead of the actual
NR_CPUS/8, which makes libnuma bail out when parsing the cpumap.
The libnuma call sched_getaffinity(0, bitmap, 4096) at first. It mean
the libnuma expect the return value of sched_getaffinity() is either len
argument or NR_CPUS. But it doesn't expect to return nr_cpu_ids.
Strictly speaking, userland requirement are
1) Glibc assume the return value mean the lengh of initialized
of mask argument. E.g. if sched_getaffinity(1024) return 128,
glibc make zero fill rest 896 byte.
2) Libnuma assume the return value can be used to guess NR_CPUS
in kernel. It assume len-arg<NR_CPUS makes -EINVAL. But
it try len=4096 at first and 4096 is always bigger than
NR_CPUS. Then, if we remove strange min_length normalization,
we never hit -EINVAL case.
sched_getaffinity() already solved this issue. This patch adapts
compat_sys_sched_getaffinity() to match the non-compat case.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Ken Werner <ken.werner@web.de>
Cc: stable@kernel.org
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes "gave up waiting for init of module libcrc32c." which
happened at boot time due to multiple parallel module loads.
The problem was a deadlock: we wait for a module to finish
initializing, but we keep the module_lock mutex so it can't complete.
In particular, this could reasonably happen if a module does a
request_module() in its initialization routine.
So we change use_module() to return an errno rather than a bool, and if
it's -EBUSY we drop the lock and wait in the caller, then reaquire the
lock.
Reported-by: Brandon Philips <brandon@ifup.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Brandon Philips <brandon@ifup.org>
This taint flag will initially be used when warning about invalid ACPI
DMAR tables.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
WARN() is used in some places to report firmware or hardware bugs that
are then worked-around. These bugs do not affect the stability of the
kernel and should not set the flag for TAINT_WARN. To allow for this,
add WARN_TAINT() and WARN_TAINT_ONCE() macros that take a taint number
as argument.
Architectures that implement warnings using trap instructions instead
of calls to warn_slowpath_*() now implement __WARN_TAINT(taint)
instead of __WARN().
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Helge Deller <deller@gmx.de>
Tested-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Currently, we can hit a nasty case with optimistic
spinning on mutexes:
CPU A tries to take a mutex, while holding the BKL
CPU B tried to take the BLK while holding the mutex
This looks like a AB-BA scenario but in practice, is
allowed and happens due to the auto-release on
schedule() nature of the BKL.
In that case, the optimistic spinning code can get us
into a situation where instead of going to sleep, A
will spin waiting for B who is spinning waiting for
A, and the only way out of that loop is the
need_resched() test in mutex_spin_on_owner().
This patch fixes it by completely disabling spinning
if we own the BKL. This adds one more detail to the
extensive list of reasons why it's a bad idea for
kernel code to be holding the BKL.
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: <stable@kernel.org>
LKML-Reference: <20100519054636.GC12389@ozlabs.org>
[ added an unlikely() attribute to the branch ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add get_online_cpus/put_online_cpus to ensure that no cpu goes
offline during the flushing of the padata percpu queues.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
yield was used to wait until all references of the internal control
structure in use are dropped before it is freed. This patch implements
padata_flush_queues which actively flushes the padata percpu queues
in this case.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
padata_get_next needs to check whether the next object that
need serialization must be parallel processed by the local cpu.
This check was wrong implemented and returned always true,
so the try_again loop in padata_reorder was never taken. This
can lead to object leaks in some rare cases due to a race that
appears with the trylock in padata_reorder. The try_again loop
was not a good idea after all, because a cpu could take that
loop frequently, so we handle this with a timer instead.
This patch adds a timer to handle the race that appears with
the trylock. If cpu1 queues an object to the reorder queue while
cpu2 holds the pd->lock but left the while loop in padata_reorder
already, cpu2 can't care for this object and cpu1 exits because
it can't get the lock. Usually the next cpu that takes the lock
cares for this object too. We need the timer just if this object
was the last one that arrives to the reorder queues. The timer
function sends it out in this case.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since the x86 XCHG ins implies LOCK, avoid the use by
using a sequence count instead.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since there is now only a single writer, we can use
local_t instead and avoid all these pesky LOCK insn.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since we can now assume there is only a single writer
to each buffer, we can remove per-cpu lock thingy and
use a simply nest-count to the same effect.
This removes the need to disable IRQs.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since we now have working per-task-per-cpu events for
a while, disallow mmap() on per-task inherited
events. Those things were a performance problem
anyway, and doing away with it allows us to optimize
the buffer somewhat by assuming there is only a
single writer.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ensure cpu bound buffers live on the right NUMA node.
Suggested-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1274114880.5605.5236.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In case the sampling buffer has no "payload" pages,
nr_pages is 0. The problem is that the error path in
perf_output_begin() skips to a label which assumes
perf_output_lock() has been issued which is not the
case. That triggers a WARN_ON() in
perf_output_unlock().
This patch fixes the problem by skipping
perf_output_unlock() in case data->nr_pages is 0.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4bf13674.014fd80a.6c82.ffffb20c@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When we've got but a single event per tracepoint
there is no reason to try and multiplex it so don't.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: Fix "integer as NULL pointer" warning.
tracing: Fix tracepoint.h DECLARE_TRACE() to allow more than one header
tracing: Make the documentation clear on trace_event boot option
ring-buffer: Wrap open-coded WARN_ONCE
tracing: Convert nop macros to static inlines
tracing: Fix sleep time function profiling
tracing: Show sample std dev in function profiling
tracing: Add documentation for trace commands mod, traceon/traceoff
ring-buffer: Make benchmark handle missed events
ring-buffer: Make non-consuming read less expensive with lots of cpus.
tracing: Add graph output support for irqsoff tracer
tracing: Have graph flags passed in to ouput functions
tracing: Add ftrace events for graph tracer
tracing: Dump either the oops's cpu source or all cpus buffers
tracing: Fix uninitialized variable of tracing/trace output
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits)
stop_machine: Move local variable closer to the usage site in cpu_stop_cpu_callback()
sched, wait: Use wrapper functions
sched: Remove a stale comment
ondemand: Make the iowait-is-busy time a sysfs tunable
ondemand: Solve a big performance issue by counting IOWAIT time as busy
sched: Intoduce get_cpu_iowait_time_us()
sched: Eliminate the ts->idle_lastupdate field
sched: Fold updating of the last_update_time_info into update_ts_time_stats()
sched: Update the idle statistics in get_cpu_idle_time_us()
sched: Introduce a function to update the idle statistics
sched: Add a comment to get_cpu_idle_time_us()
cpu_stop: add dummy implementation for UP
sched: Remove rq argument to the tracepoints
rcu: need barrier() in UP synchronize_sched_expedited()
sched: correctly place paranioa memory barriers in synchronize_sched_expedited()
sched: kill paranoia check in synchronize_sched_expedited()
sched: replace migration_thread with cpu_stop
stop_machine: reimplement using cpu_stop
cpu_stop: implement stop_cpu[s]()
sched: Fix select_idle_sibling() logic in select_task_rq_fair()
...
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (311 commits)
perf tools: Add mode to build without newt support
perf symbols: symbol inconsistency message should be done only at verbose=1
perf tui: Add explicit -lslang option
perf options: Type check all the remaining OPT_ variants
perf options: Type check OPT_BOOLEAN and fix the offenders
perf options: Check v type in OPT_U?INTEGER
perf options: Introduce OPT_UINTEGER
perf tui: Add workaround for slang < 2.1.4
perf record: Fix bug mismatch with -c option definition
perf options: Introduce OPT_U64
perf tui: Add help window to show key associations
perf tui: Make <- exit menus too
perf newt: Add single key shortcuts for zoom into DSO and threads
perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed
perf newt: Fix the 'A'/'a' shortcut for annotate
perf newt: Make <- exit the ui_browser
x86, perf: P4 PMU - fix counters management logic
perf newt: Make <- zoom out filters
perf report: Report number of events, not samples
perf hist: Clarify events_stats fields usage
...
Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c
* 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
oprofile/x86: make AMD IBS hotplug capable
oprofile/x86: notify cpus only when daemon is running
oprofile/x86: reordering some functions
oprofile/x86: stop disabled counters in nmi handler
oprofile/x86: protect cpu hotplug sections
oprofile/x86: remove CONFIG_SMP macros
oprofile/x86: fix uninitialized counter usage during cpu hotplug
oprofile/x86: remove duplicate IBS capability check
oprofile/x86: move IBS code
oprofile/x86: return -EBUSY if counters are already reserved
oprofile/x86: moving shutdown functions
oprofile/x86: reserve counter msrs pairwise
oprofile/x86: rework error handler in nmi_setup()
oprofile: update file list in MAINTAINERS file
oprofile: protect from not being in an IRQ context
oprofile: remove double ring buffering
ring-buffer: Add lost event count to end of sub buffer
tracing: Show the lost events in the trace_pipe output
ring-buffer: Add place holder recording of dropped events
tracing: Fix compile error in module tracepoints when MODULE_UNLOAD not set
...
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
rcu: remove all rcu head initializations, except on_stack initializations
rcu head introduce rcu head init on stack
Debugobjects transition check
rcu: fix build bug in RCU_FAST_NO_HZ builds
rcu: RCU_FAST_NO_HZ must check RCU dyntick state
rcu: make SRCU usable in modules
rcu: improve the RCU CPU-stall warning documentation
rcu: reduce the number of spurious RCU_SOFTIRQ invocations
rcu: permit discontiguous cpu_possible_mask CPU numbering
rcu: improve RCU CPU stall-warning messages
rcu: print boot-time console messages if RCU configs out of ordinary
rcu: disable CPU stall warnings upon panic
rcu: enable CPU_STALL_VERBOSE by default
rcu: slim down rcutiny by removing rcu_scheduler_active and friends
rcu: refactor RCU's context-switch handling
rcu: rename rcutiny rcu_ctrlblk to rcu_sched_ctrlblk
rcu: shrink rcutiny by making synchronize_rcu_bh() be inline
rcu: fix now-bogus rcu_scheduler_active comments.
rcu: Fix bogus CONFIG_PROVE_LOCKING in comments to reflect reality.
rcu: ignore offline CPUs in last non-dyntick-idle CPU check
...
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
lockdep: Reduce stack_trace usage
lockdep: No need to disable preemption in debug atomic ops
lockdep: Actually _dec_ in debug_atomic_dec
lockdep: Provide off case for redundant_hardirqs_on increment
lockdep: Simplify debug atomic ops
lockdep: Fix redundant_hardirqs_on incremented with irqs enabled
lockstat: Make lockstat counting per cpu
i8253: Convert i8253_lock to raw_spinlock
This addresses the following compiler warning:
kernel/stop_machine.c: In function 'cpu_stop_cpu_callback':
kernel/stop_machine.c:297: warning: unused variable 'work'
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <tip-3fc1f1e27a5b807791d72e5d992aa33b668a6626@git.kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The exception-trace facility on x86 and other architectures prints
traces to dmesg whenever a user space application crashes.
s390 has such a feature since ages however it is called
userprocess_debug and is enabled differently.
This patch makes sure that whenever one of the two procfs files
/proc/sys/kernel/userprocess_debug
/proc/sys/debug/exception-trace
is modified the contents of the second one changes as well.
That way we keep backwards compatibilty but also support the same
interface like other architectures do.
Besides that the output of the traces is improved since it will now
also contain the corresponding filename of the vma (when available)
where the process caused a fault or trap.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This update handles a use case where pm_qos update requests need to
silently fail if the update is being sent to a handle that is NULL.
The problem was that the original pm_qos silently fails when a request
update is passed to a parameter that has not been added to the list yet.
This update restores that behavior.
Signed-off-by: markgross <markgross@thegnar.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The new function can be used to read/write large bitmaps via /proc. A
comma separated range format is used for compact output and input
(e.g. 1,3-4,10-10).
Writing into the file will first reset the bitmap then update it
based on the given input.
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(Based on Octavian's work, and I modified a lot.)
As we are about to add another integer handling proc function a little
bit of cleanup is in order: add a few helper functions to improve code
readability and decrease code duplication.
In the process a bug is also fixed: if the user specifies a number
with more then 20 digits it will be interpreted as two integers
(e.g. 10000...13 will be interpreted as 100.... and 13).
Behavior for EFAULT handling was changed as well. Previous to this
patch, when an EFAULT error occurred in the middle of a write
operation, although some of the elements were set, that was not
acknowledged to the user (by shorting the write and returning the
number of bytes accepted). EFAULT is now treated just like any other
errors by acknowledging the amount of bytes accepted.
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the kernel is large or the profiling step small, /proc/profile
leaks data and readprofile shows silly stats, until readprofile -r
has reset the buffer: clear the prof_buffer when it is vmalloc()ed.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ftrace_trace_stack() and frace_trace_userstacke() take a
struct ring_buffer argument, not struct trace_array. Commit
e77405ad("tracing: pass around ring buffer instead of tracer")
made this change.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BE77C14.5010806@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The filter_active and enable both use an int (4 bytes each) to
set a single flag. We can save 4 bytes per event by combining the
two into a single integer.
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4894944 1018052 861512 6774508 675eec vmlinux.id
4894871 1012292 861512 6768675 674823 vmlinux.flags
This gives us another 5K in savings.
The modification of both the enable and filter fields are done
under the event_mutex, so it is still safe to combine the two.
Note: Although Mathieu gave his Acked-by, he would like it documented
that the reads of flags are not protected by the mutex. The way the
code works, these reads will not break anything, but will have a
residual effect. Since this behavior is the same even before this
patch, describing this situation is left to another patch, as this
patch does not change the behavior, but just brought it to Mathieu's
attention.
v2: Updated the event trace self test to for this change.
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Now that the trace_event structure is embedded in the ftrace_event_call
structure, there is no need for the ftrace_event_call id field.
The id field is the same as the trace_event type field.
Removing the id and re-arranging the structure brings down the tracepoint
footprint by another 5K.
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4895024 1023812 861512 6780348 6775bc vmlinux.print
4894944 1018052 861512 6774508 675eec vmlinux.id
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently, every event has its own trace_event structure. This is
fine since the structure is needed anyway. But the print function
structure (trace_event_functions) is now separate. Since the output
of the trace event is done by the class (with the exception of events
defined by DEFINE_EVENT_PRINT), it makes sense to have the class
define the print functions that all events in the class can use.
This makes a bigger deal with the syscall events since all syscall events
use the same class. The savings here is another 30K.
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4900382 1048964 861512 6810858 67ecea vmlinux.init
4900446 1049028 861512 6810986 67ed6a vmlinux.preprint
4895024 1023812 861512 6780348 6775bc vmlinux.print
To accomplish this, and to let the class know what event is being
printed, the event structure is embedded in the ftrace_event_call
structure. This should not be an issues since the event structure
was created for each event anyway.
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Multiple events may use the same method to print their data.
Instead of having all events have a pointer to their print funtions,
the trace_event structure now points to a trace_event_functions structure
that will hold the way to print ouf the event.
The event itself is now passed to the print function to let the print
function know what kind of event it should print.
This opens the door to consolidating the way several events print
their output.
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4900382 1048964 861512 6810858 67ecea vmlinux.init
4900446 1049028 861512 6810986 67ed6a vmlinux.preprint
This change slightly increases the size but is needed for the next change.
v3: Fix the branch tracer events to handle this change.
v2: Fix the new function graph tracer event calls to handle this change.
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The raw_init function pointer in the event is used to initialize
various kinds of events. The type of initialization needed is usually
classed to the kind of event it is.
Two events with the same class will always have the same initialization
function, so it makes sense to move this to the class structure.
Perhaps even making a special system structure would work since
the initialization is the same for all events within a system.
But since there's no system structure (yet), this will just move it
to the class.
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4900375 1053380 861512 6815267 67fe23 vmlinux.fields
4900382 1048964 861512 6810858 67ecea vmlinux.init
The text grew very slightly, but this is a constant growth that happened
with the changing of the C files that call the init code.
The bigger savings is the data which will be saved the more events share
a class.
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Move the defined fields from the event to the class structure.
Since the fields of the event are defined by the class they belong
to, it makes sense to have the class hold the information instead
of the individual events. The events of the same class would just
hold duplicate information.
After this change the size of the kernel dropped another 3K:
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4900252 1057412 861512 6819176 680d68 vmlinux.regs
4900375 1053380 861512 6815267 67fe23 vmlinux.fields
Although the text increased, this was mainly due to the C files
having to adapt to the change. This is a constant increase, where
new tracepoints will not increase the Text. But the big drop is
in the data size (as well as needed allocations to hold the fields).
This will give even more savings as more tracepoints are created.
Note, if just TRACE_EVENT()s are used and not DECLARE_EVENT_CLASS()
with several DEFINE_EVENT()s, then the savings will be lost. But
we are pushing developers to consolidate events with DEFINE_EVENT()
so this should not be an issue.
The kprobes define a unique class to every new event, but are dynamic
so it should not be a issue.
The syscalls however have a single class but the fields for the individual
events are different. The syscalls use a metadata to define the
fields. I moved the fields list from the event to the metadata and
added a "get_fields()" function to the class. This function is used
to find the fields. For normal events and kprobes, get_fields() just
returns a pointer to the fields list_head in the class. For syscall
events, it returns the fields list_head in the metadata for the event.
v2: Fixed the syscall fields. The syscall metadata needs a list
of fields for both enter and exit.
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch removes the register functions of TRACE_EVENT() to enable
and disable tracepoints. The registering of a event is now down
directly in the trace_events.c file. The tracepoint_probe_register()
is now called directly.
The prototypes are no longer type checked, but this should not be
an issue since the tracepoints are created automatically by the
macros. If a prototype is incorrect in the TRACE_EVENT() macro, then
other macros will catch it.
The trace_event_class structure now holds the probes to be called
by the callbacks. This removes needing to have each event have
a separate pointer for the probe.
To handle kprobes and syscalls, since they register probes in a
different manner, a "reg" field is added to the ftrace_event_class
structure. If the "reg" field is assigned, then it will be called for
enabling and disabling of the probe for either ftrace or perf. To let
the reg function know what is happening, a new enum (trace_reg) is
created that has the type of control that is needed.
With this new rework, the 82 kernel events and 618 syscall events
has their footprint dramatically lowered:
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4914025 1088868 861512 6864405 68be15 vmlinux.class
4918492 1084612 861512 6864616 68bee8 vmlinux.tracepoint
4900252 1057412 861512 6819176 680d68 vmlinux.regs
The size went from 6863829 to 6819176, that's a total of 44K
in savings. With tracepoints being continuously added, this is
critical that the footprint becomes minimal.
v5: Added #ifdef CONFIG_PERF_EVENTS around a reference to perf
specific structure in trace_events.c.
v4: Fixed trace self tests to check probe because regfunc no longer
exists.
v3: Updated to handle void *data in beginning of probe parameters.
Also added the tracepoint: check_trace_callback_type_##call().
v2: Changed the callback probes to pass void * and typecast the
value within the function.
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch adds data to be passed to tracepoint callbacks.
The created functions from DECLARE_TRACE() now need a mandatory data
parameter. For example:
DECLARE_TRACE(mytracepoint, int value, value)
Will create the register function:
int register_trace_mytracepoint((void(*)(void *data, int value))probe,
void *data);
As the first argument, all callbacks (probes) must take a (void *data)
parameter. So a callback for the above tracepoint will look like:
void myprobe(void *data, int value)
{
}
The callback may choose to ignore the data parameter.
This change allows callbacks to register a private data pointer along
with the function probe.
void mycallback(void *data, int value);
register_trace_mytracepoint(mycallback, mydata);
Then the mycallback() will receive the "mydata" as the first parameter
before the args.
A more detailed example:
DECLARE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status));
/* In the C file */
DEFINE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status));
[...]
trace_mytracepoint(status);
/* In a file registering this tracepoint */
int my_callback(void *data, int status)
{
struct my_struct my_data = data;
[...]
}
[...]
my_data = kmalloc(sizeof(*my_data), GFP_KERNEL);
init_my_data(my_data);
register_trace_mytracepoint(my_callback, my_data);
The same callback can also be registered to the same tracepoint as long
as the data registered is different. Note, the data must also be used
to unregister the callback:
unregister_trace_mytracepoint(my_callback, my_data);
Because of the data parameter, tracepoints declared this way can not have
no args. That is:
DECLARE_TRACE(mytracepoint, TP_PROTO(void), TP_ARGS());
will cause an error.
If no arguments are needed, a new macro can be used instead:
DECLARE_TRACE_NOARGS(mytracepoint);
Since there are no arguments, the proto and args fields are left out.
This is part of a series to make the tracepoint footprint smaller:
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4914025 1088868 861512 6864405 68be15 vmlinux.class
4918492 1084612 861512 6864616 68bee8 vmlinux.tracepoint
Again, this patch also increases the size of the kernel, but
lays the ground work for decreasing it.
v5: Fixed net/core/drop_monitor.c to handle these updates.
v4: Moved the DECLARE_TRACE() DECLARE_TRACE_NOARGS out of the
#ifdef CONFIG_TRACE_POINTS, since the two are the same in both
cases. The __DECLARE_TRACE() is what changes.
Thanks to Frederic Weisbecker for pointing this out.
v3: Made all register_* functions require data to be passed and
all callbacks to take a void * parameter as its first argument.
This makes the calling functions comply with C standards.
Also added more comments to the modifications of DECLARE_TRACE().
v2: Made the DECLARE_TRACE() have the ability to pass arguments
and added a new DECLARE_TRACE_NOARGS() for tracepoints that
do not need any arguments.
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch creates a ftrace_event_class struct that event structs point to.
This class struct will be made to hold information to modify the
events. Currently the class struct only holds the events system name.
This patch slightly increases the size, but this change lays the ground work
of other changes to make the footprint of tracepoints smaller.
With 82 standard tracepoints, and 618 system call tracepoints
(two tracepoints per syscall: enter and exit):
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4914025 1088868 861512 6864405 68be15 vmlinux.class
This patch also cleans up some stale comments in ftrace.h.
v2: Fixed missing semi-colon in macro.
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When an interrupt is disabled and torn down, the CPU mask returned
through affinity_hint right now is all CPUs. Also, for drivers that
don't provide an affinity_hint mask, this can be misleading. There
should be no hint at all, meaning an empty CPU mask.
[ tglx: use zalloc_cpumask_var instead of clearing it under the lock ]
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Cc: davem@davemloft.net
Cc: arjan@linux.jf.intel.com
Cc: bhutchings@solarflare.com
LKML-Reference: <20100505205638.5426.87189.stgit@ppwaskie-hc2.jf.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Oleg Nesterov
Neil Horman
Mike Frysinger
Jack Steiner
Kirill A. Shutemov
Stanislaw Gruszka
Thomas Gleixner
Linus Torvalds
J. R. Okajima
Steven Rostedt
Andy Shevchenko
Wenji Huang
Haicheng Li
minskey guo
Mel Gorman
Miao Xie
Peter Zijlstra
Jeff Chua
Randy Dunlap
Jens Axboe
Chris Wright
NeilBrown
Peter Zijlstra
Jason Wessel
Michal Nazarewicz
Frederic Weisbecker
Ingo Molnar
KOSAKI Motohiro
Dmitry Torokhov
Rusty Russell
Ben Hutchings
Tony Breeds
David S. Miller
Steffen Klassert
Stephane Eranian
James Bottomley
James Morris
Heiko Carstens
Mark Gross
Octavian Purdila
Amerigo Wang
Hugh Dickins
Li Zefan
Peter P Waskiewicz Jr