Davide Libenzi 4ede816ac3 epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key() ... This patchset introduces wakeup hints for some of the most popular (from epoll POV) devices, so that epoll code can avoid spurious wakeups on its waiters. The problem with epoll is that the callback-based wakeups do not, ATM, carry any information about the events the wakeup is related to. So the only choice epoll has (not being able to call f_op->poll() from inside the callback), is to add the file* to a ready-list and resolve the real events later on, at epoll_wait() (or its own f_op->poll()) time. This can cause spurious wakeups, since the wake_up() itself might be for an event the caller is not interested into. The rate of these spurious wakeup can be pretty high in case of many network sockets being monitored. By allowing devices to report the events the wakeups refer to (at least the two major classes - POLLIN/POLLOUT), we are able to spare useless wakeups by proper handling inside the epoll's poll callback. Epoll will have in any case to call f_op->poll() on the file* later on, since the change to be done in order to have the full event set sent via wakeup, is too invasive for the way our f_op->poll() system works (the full event set is calculated inside the poll function - there are too many of them to even start thinking the change - also poll/select would need change too). Epoll is changed in a way that both devices which send event hints, and the ones that don't, are correctly handled. The former will gain some efficiency though. As a general rule for devices, would be to add an event mask by using key-aware wakeup macros, when making up poll wait queues. I tested it (together with the epoll's poll fix patch Andrew has in -mm) and wakeups for the supported devices are correctly filtered. Test program available here: http://www.xmailserver.org/epoll_test.c This patch: Nothing revolutionary here. Just using the available "key" that our wakeup core already support. The __wake_up_locked_key() was no brainer, since both __wake_up_locked() and __wake_up_locked_key() are thin wrappers around __wake_up_common(). The __wake_up_sync() function had a body, so the choice was between borrowing the body for __wake_up_sync_key() and calling it from __wake_up_sync(), or make an inline and calling it from both. I chose the former since in most archs it all resolves to "mov $0, REG; jmp ADDR". Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: William Lee Irwin III <wli@movementarian.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2009-04-01 08:59:20 -07:00
..
irq	PM: Introduce functions for suspending and resuming device interrupts	2009-03-30 21:46:54 +02:00
power	pm: rework includes, remove arch ifdefs	2009-04-01 08:59:16 -07:00
time	Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-03-26 16:05:42 -07:00
trace	Merge commit 'origin/master' into next	2009-03-11 17:10:07 +11:00
.gitignore	Update kernel/.gitignore with new auto-generated files	2008-02-09 23:27:01 -08:00
Kconfig.freezer	container freezer: implement freezer cgroup subsystem	2008-10-20 08:52:34 -07:00
Kconfig.hz	sched: fix SCHED_HRTICK dependency	2008-07-28 14:37:38 +02:00
Kconfig.preempt	rcu: provide RCU options on non-preempt architectures too	2008-12-25 09:31:28 +01:00
Makefile	PM: fix build for CONFIG_PM unset	2009-02-21 14:17:17 -08:00
acct.c	[CVE-2009-0029] System call wrappers part 04	2009-01-14 14:15:19 +01:00
async.c	async: remove the temporary (2.6.29) "async is off by default" code	2009-03-28 13:05:30 -07:00
audit.c	[PATCH] fix broken timestamps in AVC generated by kernel threads	2008-12-09 02:27:41 -05:00
audit.h	fixing audit rule ordering mess, part 1	2009-01-04 15:14:41 -05:00
audit_tree.c	audit: validate comparison operations, store them in sane form	2009-01-04 15:14:42 -05:00
auditfilter.c	audit: validate comparison operations, store them in sane form	2009-01-04 15:14:42 -05:00
auditsc.c	make sure that filterkey of task,always rules is reported	2009-01-04 15:14:42 -05:00
backtracetest.c	backtrace: replace timer with tasklet + completions	2008-06-27 18:09:16 +02:00
bounds.c	Add kbuild.h that contains common definitions for kbuild users	2008-04-29 08:06:29 -07:00
capability.c	[CVE-2009-0029] System call wrappers part 04	2009-01-14 14:15:19 +01:00
cgroup.c	vfs: simple_set_mnt() should return void	2009-03-27 14:44:03 -04:00
cgroup_debug.c	cgroups: fix probable race with put_css_set[_taskexit] and find_css_set	2008-10-20 08:52:38 -07:00
cgroup_freezer.c	freezer_cg: disable writing freezer.state of root cgroup	2008-11-12 17:17:16 -08:00
compat.c	Allow times and time system calls to return small negative values	2009-01-06 15:59:13 -08:00
configs.c	kernel/configs.c: remove useless comments	2008-10-20 08:52:34 -07:00
cpu.c	cpumask: use set_cpu_active in init/main.c	2009-03-30 22:05:12 +10:30
cpuset.c	cpuset: fix possible deadlock in async_rebuild_sched_domains	2009-01-19 02:44:00 +01:00
cred-internals.h	CRED: Inaugurate COW credentials	2008-11-14 10:39:23 +11:00
cred.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6	2009-01-09 13:59:25 -08:00
delayacct.c	schedstat: consolidate per-task cpu runtime stats	2008-12-18 13:54:01 +01:00
dma-coherent.c	dma-coherent: Restore dma_alloc_from_coherent() large alloc fall back policy.	2009-01-21 18:51:53 +09:00
dma.c	kernel/dma.c: remove a CVS keyword	2008-10-16 11:21:30 -07:00
exec_domain.c	[CVE-2009-0029] System call wrappers part 04	2009-01-14 14:15:19 +01:00
exit.c	Merge branch 'linus' into x86/apic	2009-02-13 09:44:22 +01:00
extable.c	Merge branch 'core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2008-12-30 16:10:19 -08:00
fork.c	cpumask: use mm_cpumask() wrapper: kernel/fork.c	2009-03-30 22:05:13 +10:30
freezer.c	freezer_cg: use thaw_process() in unfreeze_cgroup()	2008-10-30 11:38:45 -07:00
futex.c	futex: remove the pointer math from double_unlock_hb, fix	2009-03-13 10:32:07 +01:00
futex_compat.c	CRED: Use RCU to access another task's creds and to release a task's own creds	2008-11-14 10:39:19 +11:00
hrtimer.c	hrtimer: prevent negative expiry value after clock_was_set()	2009-01-30 22:35:34 +01:00
itimer.c	timers: split process wide cpu clocks/timers	2009-02-05 13:04:33 +01:00
kallsyms.c	Revert "kbuild: strip generated symbols from *.ko"	2009-01-14 21:38:20 +01:00
kexec.c	kexec: Change kexec jump code ordering	2009-03-30 21:46:55 +02:00
kfifo.c	…
kgdb.c	kgdb: call touch_softlockup_watchdog on resume	2008-10-06 13:50:59 -05:00
kmod.c	cpumask: remove dangerous CPU_MASK_ALL_PTR, &CPU_MASK_ALL	2009-03-30 22:05:11 +10:30
kprobes.c	kprobes: check CONFIG_FREEZER instead of CONFIG_PM	2009-01-16 14:32:17 -05:00
ksysfs.c	kernel/ksysfs.c:fix dependence on CONFIG_NET	2009-01-06 10:44:31 -08:00
kthread.c	cpumask: remove dangerous CPU_MASK_ALL_PTR, &CPU_MASK_ALL	2009-03-30 22:05:11 +10:30
latencytop.c	sched, latencytop: incorporate review feedback from Andrew Morton	2009-02-11 10:18:04 +01:00
lockdep.c	lockdep: fix deadlock in lockdep_trace_alloc	2009-03-30 23:19:24 +02:00
lockdep_internals.h	lockdep: get_user_chars() redo	2009-02-14 23:28:22 +01:00
lockdep_proc.c	lockstat: warn about disabled lock debugging	2009-02-14 23:28:28 +01:00
lockdep_states.h	lockdep: move state bit definitions around	2009-02-14 23:27:59 +01:00
marker.c	markers/tracpoints: fix non-modular build	2008-11-16 09:52:03 +01:00
module.c	Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2	2009-03-27 17:28:43 +01:00
mutex-debug.c	mutex: implement adaptive spinning	2009-01-14 18:09:02 +01:00
mutex-debug.h	mutex: implement adaptive spinning	2009-01-14 18:09:02 +01:00
mutex.c	mutex: adaptive spinnning, performance tweaks	2009-01-14 19:03:54 +01:00
mutex.h	mutex: implement adaptive spinning	2009-01-14 18:09:02 +01:00
notifier.c	Merge commit 'v2.6.28-rc6' into core/debug	2008-11-26 08:22:50 +01:00
ns_cgroup.c	ns_cgroup: remove unused spinlock	2009-01-08 08:31:02 -08:00
nsproxy.c	User namespaces: set of cleanups (v2)	2008-11-24 18:57:41 -05:00
panic.c	stackprotector: update make rules	2009-02-10 00:41:54 +01:00
params.c	Fix compile warning in kernel/params.c	2008-10-23 12:09:00 -07:00
pid.c	pid: generalize task_active_pid_ns	2009-01-08 08:31:12 -08:00
pid_namespace.c	pid_ns: (BUG 11391) change ->child_reaper when init->group_leader exits	2008-09-02 19:21:38 -07:00
pm_qos_params.c	pm_qos_requirement might sleep	2008-09-02 19:21:40 -07:00
posix-cpu-timers.c	posix timers: fix RLIMIT_CPU && fork()	2009-03-23 20:43:35 +01:00
posix-timers.c	[CVE-2009-0029] System call wrappers part 05	2009-01-14 14:15:20 +01:00
printk.c	PM: Fix suspend_console and resume_console to use only one semaphore	2009-02-21 14:17:18 -08:00
profile.c	profiling: fix broken profiling regression	2009-02-10 00:50:37 +01:00
ptrace.c	[CVE-2009-0029] System call wrappers part 27	2009-01-14 14:15:29 +01:00
rcuclassic.c	rcu: Teach RCU that idle task is not quiscent state at boot	2009-02-26 04:08:14 +01:00
rcupdate.c	rcu: Teach RCU that idle task is not quiscent state at boot	2009-02-26 04:08:14 +01:00
rcupreempt.c	rcu: Teach RCU that idle task is not quiscent state at boot	2009-02-26 04:08:14 +01:00
rcupreempt_trace.c	"Tree RCU": scalable classic RCU implementation	2008-12-18 21:56:04 +01:00
rcutorture.c	cpumask: convert rcutorture.c	2009-03-30 22:05:16 +10:30
rcutree.c	rcu: Teach RCU that idle task is not quiscent state at boot	2009-02-26 04:08:14 +01:00
rcutree_trace.c	"Tree RCU": scalable classic RCU implementation	2008-12-18 21:56:04 +01:00
relay.c	timers: add mod_timer_pending()	2009-02-18 19:26:33 +01:00
res_counter.c	memcg: memory cgroup resource counters for hierarchy	2009-01-08 08:31:05 -08:00
resource.c	resources: fix parameter name and kernel-doc	2009-01-15 16:39:38 -08:00
rtmutex-debug.c	Don't operate with pid_t in rtmutex tester	2008-02-08 09:22:41 -08:00
rtmutex-debug.h	…
rtmutex-tester.c	sysdev: Pass the attribute to the low level sysdev show/store function	2008-07-21 21:55:02 -07:00
rtmutex.c	hrtimer: convert kernel/* to the new hrtimer apis	2008-09-05 21:35:13 -07:00
rtmutex.h	…
rtmutex_common.h	Don't operate with pid_t in rtmutex tester	2008-02-08 09:22:41 -08:00
rwsem.c	…
sched.c	epoll keyed wakeups: add __wake_up_locked_key() and __wake_up_sync_key()	2009-04-01 08:59:20 -07:00
sched_clock.c	sched_clock: cleanups	2009-02-26 21:56:07 +01:00
sched_cpupri.c	sched: fix section mismatch	2009-01-06 11:07:15 +01:00
sched_cpupri.h	cpumask: remove cpumask_t from core	2009-03-30 22:05:17 +10:30
sched_debug.c	sched: remove unused fields from struct rq	2009-03-24 23:16:51 +01:00
sched_fair.c	Merge branch 'sched/urgent'; commit 'v2.6.29-rc5' into sched/core	2009-02-15 21:15:16 +01:00
sched_features.h	Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-03-30 17:17:35 -07:00
sched_idletask.c	sched: add CONFIG_SMP consistency	2008-10-22 10:01:52 +02:00
sched_rt.c	Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2	2009-03-27 17:28:43 +01:00
sched_stats.h	sched: remove unused fields from struct rq	2009-03-24 23:16:51 +01:00
seccomp.c	x86-64: seccomp: fix 32/64 syscall hole	2009-03-02 15:41:30 -08:00
semaphore.c	semaphore: __down_common: use signal_pending_state()	2008-08-05 14:33:47 -07:00
signal.c	fix ptrace slowness	2009-03-23 09:22:31 -07:00
smp.c	generic-ipi: use per cpu data for single cpu ipi calls	2009-01-30 18:31:08 +01:00
softirq.c	Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2	2009-03-27 17:28:43 +01:00
softlockup.c	softlock: fix false panic which can occur if softlockup_thresh is reduced	2009-01-14 11:48:07 +01:00
spinlock.c	lockdep: spin_lock_nest_lock(), checkpatch fixes	2008-08-13 13:56:51 +02:00
srcu.c	…
stacktrace.c	stacktrace: provide save_stack_trace_tsk() weak alias	2008-12-25 11:44:43 +01:00
stop_machine.c	cpumask: remove cpumask_t from core	2009-03-30 22:05:17 +10:30
sys.c	sched: don't allow setuid to succeed if the user does not have rt bandwidth	2009-02-27 11:11:53 +01:00
sys_ni.c	[CVE-2009-0029] Make sys_syslog a conditional system call	2009-01-14 14:15:16 +01:00
sysctl.c	mm: fix proc_dointvec_userhz_jiffies "breakage"	2009-04-01 08:59:13 -07:00
sysctl_check.c	net: add ARP notify option for devices	2009-02-01 01:04:33 -08:00
taskstats.c	cpumask: convert rest of files in kernel/	2009-01-01 10:12:28 +10:30
test_kprobes.c	kprobes: add tests for register_kprobes	2009-01-06 15:59:20 -08:00
time.c	[CVE-2009-0029] System call wrappers part 01	2009-01-14 14:15:18 +01:00
timeconst.pl	Make constants in kernel/timeconst.h fixed 64 bits	2008-05-02 16:18:42 -07:00
timer.c	Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-03-30 17:17:35 -07:00
tracepoint.c	markers/tracpoints: fix non-modular build	2008-11-16 09:52:03 +01:00
tsacct.c	Fix fixpoint divide exception in acct_update_integrals	2009-03-09 08:13:35 -07:00
uid16.c	[CVE-2009-0029] System call wrappers part 19	2009-01-14 14:15:26 +01:00
up.c	smp_call_function_single(): be slightly less stupid, fix #2	2009-01-12 16:04:37 +01:00
user.c	Merge branch 'master' into next	2009-03-24 10:52:46 +11:00
user_namespace.c	Fix recursive lock in free_uid()/free_user_ns()	2009-02-27 16:26:21 -08:00
utsname.c	removed unused #include <linux/version.h>'s	2008-08-23 12:14:12 -07:00
utsname_sysctl.c	sysctl: simplify ->strategy	2008-10-16 11:21:47 -07:00
wait.c	wait: prevent exclusive waiter starvation	2009-02-05 12:56:48 -08:00
workqueue.c	cpumask: use new cpumask_ functions in core code.	2009-03-30 22:05:16 +10:30