iSeries dependent drivers fail to build, when CONFIG_VIOPATH is disabled.
Fix the problem by making those drivers select it.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Enable RELOCATABLE option if user selects CRASH_DUMP option. Without this
patch user has to first select RELOCATABLE option and then has to enable
CRASH_DUMP option.
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Dave Liu <daveliu@freescale.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
So change the flags member of struct spu from u64 to unsigned long.
This change will also prevent some warnings when we change u64 to unsigned
long long.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
These ioctls take a struct serial_rs485
(see linux/serial.h) as argument. They are already available
on x86. This patch adds them for the powerpc architecture.
Signed-off-by: Matthias Fuchs <mfuchs@ma-fu.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
X has been failing to start on my quad G5 powermac since commit
1fd0f52583 ("powerpc: Fix domain numbers
in /proc on 64-bit") went in. The reason is that the change allows X
to see the PCI-PCI bridge above the video card (previously it was
obscured by the fact that there were two "00" directories in
/proc/bus/pci), and the pciconfig_iobase system call on the bridge is
failing because of a hack that we have to return information about the
AGP bus when X asks about bus 0. This machine doesn't have an AGP bus
(it has PCI Express) and so the pciconfig_iobase call is returning -1,
which ultimately causes X to fail to start.
This fixes it by checking that we have an AGP bridge before
redirecting the pciconfig_iobase call to return information about the
AGP bus. With this, X starts successfully both on a quad G5 with
PCI Express and on an older dual G5 with AGP.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
SPIN_LOCK_UNLOCKED is deprecated. The following makes the change suggested
in Documentation/spinlocks.txt
The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@
declarer name DEFINE_SPINLOCK;
identifier xxx_lock;
@@
- spinlock_t xxx_lock = SPIN_LOCK_UNLOCKED;
+ DEFINE_SPINLOCK(xxx_lock);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
SPIN_LOCK_UNLOCKED is deprecated. The following makes the change suggested
in Documentation/spinlocks.txt
The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@
declarer name DEFINE_SPINLOCK;
identifier xxx_lock;
@@
- spinlock_t xxx_lock = SPIN_LOCK_UNLOCKED;
+ DEFINE_SPINLOCK(xxx_lock);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The current code for providing processor cache information in sysfs
has the following deficiencies:
- several complex functions that are hard to understand
- implicit recursion (cache_desc_release -> kobject_put -> cache_desc_release)
- explicit recursion (create_cache_index_info)
- use of two per-cpu arrays when one would suffice
- duplication of work on systems where CPUs share cache
Also, when I looked at implementing support for a shared_cpu_map
attribute, it was pretty much impossible to handle hotplug without
checking every single online CPU's cache_desc list and fixing things
up... not that this is a hot path, but it would have introduced
O(n^2)-ish behavior during boot. Addressing this involved rethinking
the core data structures used, which didn't lend itself to an
incremental approach.
This implementation maintains a "forest" (potentially more than one
tree) of cache objects which reflects the system's cache topology.
Cache objects are instantiated as needed as CPUs come online. A
per-cpu array is used mainly for sysfs-related bookkeeping; the
objects in the array just point to the appropriate points in the
forest.
This maintains compatibility with the existing code and includes some
enhancements:
- Implement the shared_cpu_map attribute, which is essential for
enabling userspace to discover the system's overall cache topology.
- Use cache-block-size properties if cache-line-size is not available.
I chose to place this implementation in a new file since it would have
roughly doubled the size of sysfs.c, which is already kind of messy.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The non-zero return from the prepare callback is returned by sys_kexec_load()
to userspace, indicating that kexec is not supported on the machine.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch makes the default install script (arch/powerpc/boot/install.sh)
copy the bootable image files into the install directory. Before this
patch only the vmlinux image file was copied.
This patch makes the default 'make install' command useful for embedded
development when $(INSTALL_PATH) is set in the environment.
As a side effect, this patch changes the calling convention of the
install.sh script. Instead of a single 5th parameter, the script is now
passed a list of all the target images stored in the $(image-y) Makefile
variable. This should be backwards compatible with existing install scripts
since it just adds additional arguments and does not change existing ones.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Both users of careful_allocation() immediately memset() the
result. So, just do it in one place.
Also give careful_allocation() a 'z' prefix to bring it in
line with kzmalloc() and friends.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Since we memset() the result in both of the uses here,
just make careful_alloc() return a virtual address.
Also, add a separate variable to store the physial
address that comes back from the lmb_alloc() functions.
This makes it less likely that someone will screw it up
forgetting to convert before returning since the vaddr
is always in a void* and the paddr is always in an
unsigned long.
I admit this is arbitrary since one of its users needs
a paddr and one a vaddr, but it does remove a good
number of casts.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
If we fail a bootmem allocation, the bootmem code itself
panics. No need to redo it here.
Also change the wording of the other panic. We don't
strictly have to allocate memory on the specified node.
It is just a hint and that node may not even *have* any
memory on it. In that case we can and do fall back to
other nodes.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The behavior in careful_allocation() really confused me
at first. Add a comment to hopefully make it easier
on the next doofus that looks at it.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch fixes some unbalanced OF node references in the
powermac code
Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
There's a problem on some embedded platforms when we re-assign
everything on PCI, such as 44x. The generic code tries to avoid
assigning devices to addresses overlapping the low legacy
addresses such as VGA hard decoded areas using constants that
are unfortunately no good for us, as they don't take into account
the address translation we do to access PCI busses.
Thus we end up allocating things like IO BARs to 0, which is
technically legal, but will shadow hard decoded ports for use
by things like VGA cards.
This works around it by attempting to reserve legacy regions
before we try to assign addresses.
NOTE: This may have nasty side effects in cases I haven't tested
yet:
- We try to use FW mappings (ie. powermac) and the FW has allocated
a conflicting address over those legacy regions. This will typically
happen. I would expect the new code to just fail with an informative
message without harm but I haven't had a chance to test that scenario
yet.
- A device with fixed BARs overlapping those legacy addresses such
as an IDE controller in legacy mode is in the system. I don't know
for sure yet what will happen there, I have to test :-)
Ideally, we should change PCIBIOS_MIN_IO/MIN_MEM accross the board
to take a bus pointer so they can provide appropriate per-bus translated
values to the generic code but that's a more invasive patch. I will
do that in the future, but in the meantime, this fixes the problem
locally
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (98 commits)
PCI PM: Put PM callbacks in the order of execution
PCI PM: Run default PM callbacks for all devices using new framework
PCI PM: Register power state of devices during initialization
PCI PM: Call pci_fixup_device from legacy routines
PCI PM: Rearrange code in pci-driver.c
PCI PM: Avoid touching devices behind bridges in unknown state
PCI PM: Move pci_has_legacy_pm_support
PCI PM: Power-manage devices without drivers during suspend-resume
PCI PM: Add suspend counterpart of pci_reenable_device
PCI PM: Fix poweroff and restore callbacks
PCI: Use msleep instead of cpu_relax during ASPM link retraining
PCI: PCIe portdrv: Add kerneldoc comments to remining core funtions
PCI: PCIe portdrv: Rearrange code so that related things are together
PCI: PCIe portdrv: Fix suspend and resume of PCI Express port services
PCI: PCIe portdrv: Add kerneldoc comments to some core functions
x86/PCI: Do not use interrupt links for devices using MSI-X
net: sfc: Use pci_clear_master() to disable bus mastering
PCI: Add pci_clear_master() as opposite of pci_set_master()
PCI hotplug: remove redundant test in cpq hotplug
PCI: pciehp: cleanup register and field definitions
...
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (123 commits)
wimax/i2400m: add CREDITS and MAINTAINERS entries
wimax: export linux/wimax.h and linux/wimax/i2400m.h with headers_install
i2400m: Makefile and Kconfig
i2400m/SDIO: TX and RX path backends
i2400m/SDIO: firmware upload backend
i2400m/SDIO: probe/disconnect, dev init/shutdown and reset backends
i2400m/SDIO: header for the SDIO subdriver
i2400m/USB: TX and RX path backends
i2400m/USB: firmware upload backend
i2400m/USB: probe/disconnect, dev init/shutdown and reset backends
i2400m/USB: header for the USB bus driver
i2400m: debugfs controls
i2400m: various functions for device management
i2400m: RX and TX data/control paths
i2400m: firmware loading and bootrom initialization
i2400m: linkage to the networking stack
i2400m: Generic probe/disconnect, reset and message passing
i2400m: host/device procotol and core driver definitions
i2400m: documentation and instructions for usage
wimax: Makefile, Kconfig and docbook linkage for the stack
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits)
trivial: chack -> check typo fix in main Makefile
trivial: Add a space (and a comma) to a printk in 8250 driver
trivial: Fix misspelling of "firmware" in docs for ncr53c8xx/sym53c8xx
trivial: Fix misspelling of "firmware" in powerpc Makefile
trivial: Fix misspelling of "firmware" in usb.c
trivial: Fix misspelling of "firmware" in qla1280.c
trivial: Fix misspelling of "firmware" in a100u2w.c
trivial: Fix misspelling of "firmware" in megaraid.c
trivial: Fix misspelling of "firmware" in ql4_mbx.c
trivial: Fix misspelling of "firmware" in acpi_memhotplug.c
trivial: Fix misspelling of "firmware" in ipw2100.c
trivial: Fix misspelling of "firmware" in atmel.c
trivial: Fix misspelled firmware in Kconfig
trivial: fix an -> a typos in documentation and comments
trivial: fix then -> than typos in comments and documentation
trivial: update Jesper Juhl CREDITS entry with new email
trivial: fix singal -> signal typo
trivial: Fix incorrect use of "loose" in event.c
trivial: printk: fix indentation of new_text_line declaration
trivial: rtc-stk17ta8: fix sparse warning
...
Use the generic pci_swizzle_interrupt_pin() instead of arch-specific code.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
A published errata for ppc440epx states, that when running Linux with
both EHCI and OHCI modules loaded, the EHCI module experiences a fatal
error when a high-speed device is connected to the USB2.0, and
functions normally if OHCI module is not loaded.
There used to be recommendation to use only hi-speed or full-speed
devices with specific conditions, when respective module was unloaded.
Later, it was observed that ohci suspend is enough to keep things
going, and it was turned into workaround, as explained below.
Quote from original descriprion:
The 440EPx USB 2.0 Host controller is an EHCI compliant controller. In
USB 2.0 Host controllers, each EHCI controller has one or more companion
controllers, which may be OHCI or UHCI. An USB 2.0 Host controller will
contain one or more ports. For each port, only one of the controllers
is connected at any one time. In the 440EPx, there is only one OHCI
companion controller, and only one USB 2.0 Host port.
All ports on an USB 2.0 controller default to the companion
controller. If you load only an ohci driver, it will have control of
the ports and any deviceplugged in will operate, although high speed
devices will be forced to operate at full speed. When an ehci driver
is loaded, it explicitly takes control of the ports. If there is a
device connected, and / or every time there is a new device connected,
the ehci driver determines if the device is high speed or not. If it
is high speed, the driver retains control of the port. If it is not,
the driver explicitly gives the companion controller control of the
port.
The is a software workaround that uses
Initial version of the software workaround was posted to
linux-usb-devel:
http://www.mail-archive.com/linux-usb-devel@lists.sourceforge.net/msg54019.html
and later available from amcc.com:
http://www.amcc.com/Embedded/Downloads/download.html?cat=1&family=15&ins=2
The patch below is generally based on the latter, but reworked to
powerpc/of_device USB drivers, and uses a few devicetree inquiries to
get rid of (some) hardcoded defines.
Signed-off-by: Vitaly Bordug <vitb@kernel.crashing.org>
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add kprobe_insn_mutex for protecting kprobe_insn_pages hlist, and remove
kprobe_mutex from architecture dependent code.
This allows us to call arch_remove_kprobe() (and free_insn_slot) while
holding kprobe_mutex.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The atomic_t type cannot currently be used in some header files because it
would create an include loop with asm/atomic.h. Move the type definition
to linux/types.h to break the loop.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Show node to memory section relationship with symlinks in sysfs
Add /sys/devices/system/node/nodeX/memoryY symlinks for all
the memory sections located on nodeX. For example:
/sys/devices/system/node/node1/memory135 -> ../../memory/memory135
indicates that memory section 135 resides on node1.
Also revises documentation to cover this change as well as updating
Documentation/ABI/testing/sysfs-devices-memory to include descriptions
of memory hotremove files 'phys_device', 'phys_index', and 'state'
that were previously not described there.
In addition to it always being a good policy to provide users with
the maximum possible amount of physical location information for
resources that can be hot-added and/or hot-removed, the following
are some (but likely not all) of the user benefits provided by
this change.
Immediate:
- Provides information needed to determine the specific node
on which a defective DIMM is located. This will reduce system
downtime when the node or defective DIMM is swapped out.
- Prevents unintended onlining of a memory section that was
previously offlined due to a defective DIMM. This could happen
during node hot-add when the user or node hot-add assist script
onlines _all_ offlined sections due to user or script inability
to identify the specific memory sections located on the hot-added
node. The consequences of reintroducing the defective memory
could be ugly.
- Provides information needed to vary the amount and distribution
of memory on specific nodes for testing or debugging purposes.
Future:
- Will provide information needed to identify the memory
sections that need to be offlined prior to physical removal
of a specific node.
Symlink creation during boot was tested on 2-node x86_64, 2-node
ppc64, and 2-node ia64 systems. Symlink creation during physical
memory hot-add tested on a 2-node x86_64 system.
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The KernelPageSize entry in /proc/pid/smaps is the pagesize used by the
kernel to back a VMA. This matches the size used by the MMU in the
majority of cases. However, one counter-example occurs on PPC64 kernels
whereby a kernel using 64K as a base pagesize may still use 4K pages for
the MMU on older processor. To distinguish, this patch reports
MMUPageSize as the pagesize used by the MMU in /proc/pid/smaps.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix misspelling of "firmware" in powerpc Makefile
It's spelled "firmware".
Signed-off-by: Nick Andrew <nick@nick-andrew.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
... and don't bother in callers. Don't bother with zeroing i_blocks,
while we are at it - it's already been zeroed.
i_mode is not worth the effort; it has no common default value.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'cpus4096-for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (77 commits)
x86: setup_per_cpu_areas() cleanup
cpumask: fix compile error when CONFIG_NR_CPUS is not defined
cpumask: use alloc_cpumask_var_node where appropriate
cpumask: convert shared_cpu_map in acpi_processor* structs to cpumask_var_t
x86: use cpumask_var_t in acpi/boot.c
x86: cleanup some remaining usages of NR_CPUS where s/b nr_cpu_ids
sched: put back some stack hog changes that were undone in kernel/sched.c
x86: enable cpus display of kernel_max and offlined cpus
ia64: cpumask fix for is_affinity_mask_valid()
cpumask: convert RCU implementations, fix
xtensa: define __fls
mn10300: define __fls
m32r: define __fls
h8300: define __fls
frv: define __fls
cris: define __fls
cpumask: CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
cpumask: zero extra bits in alloc_cpumask_var_node
cpumask: replace for_each_cpu_mask_nr with for_each_cpu in kernel/time/
cpumask: convert mm/
...
* 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits)
x86: export vector_used_by_percpu_irq
x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and()
sched: nominate preferred wakeup cpu, fix
x86: fix lguest used_vectors breakage, -v2
x86: fix warning in arch/x86/kernel/io_apic.c
sched: fix warning in kernel/sched.c
sched: move test_sd_parent() to an SMP section of sched.h
sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0
sched: activate active load balancing in new idle cpus
sched: bias task wakeups to preferred semi-idle packages
sched: nominate preferred wakeup cpu
sched: favour lower logical cpu number for sched_mc balance
sched: framework for sched_mc/smt_power_savings=N
sched: convert BALANCE_FOR_xx_POWER to inline functions
x86: use possible_cpus=NUM to extend the possible cpus allowed
x86: fix cpu_mask_to_apicid_and to include cpu_online_mask
x86: update io_apic.c to the new cpumask code
x86: Introduce topology_core_cpumask()/topology_thread_cpumask()
x86: xen: use smp_call_function_many()
x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c
...
Fixed up trivial conflict in kernel/time/tick-sched.c manually
* 'kvm-updates/2.6.29' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: (140 commits)
KVM: MMU: handle large host sptes on invlpg/resync
KVM: Add locking to virtual i8259 interrupt controller
KVM: MMU: Don't treat a global pte as such if cr4.pge is cleared
MAINTAINERS: Maintainership changes for kvm/ia64
KVM: ia64: Fix kvm_arch_vcpu_ioctl_[gs]et_regs()
KVM: x86: Rework user space NMI injection as KVM_CAP_USER_NMI
KVM: VMX: Fix pending NMI-vs.-IRQ race for user space irqchip
KVM: fix handling of ACK from shared guest IRQ
KVM: MMU: check for present pdptr shadow page in walk_shadow
KVM: Consolidate userspace memory capability reporting into common code
KVM: Advertise the bug in memory region destruction as fixed
KVM: use cpumask_var_t for cpus_hardware_enabled
KVM: use modern cpumask primitives, no cpumask_t on stack
KVM: Extract core of kvm_flush_remote_tlbs/kvm_reload_remote_mmus
KVM: set owner of cpu and vm file operations
anon_inodes: use fops->owner for module refcount
x86: KVM guest: kvm_get_tsc_khz: return khz, not lpj
KVM: MMU: prepopulate the shadow on invlpg
KVM: MMU: skip global pgtables on sync due to cr3 switch
KVM: MMU: collapse remote TLB flushes on root sync
...
Impact: New API
The old topology_core_siblings() and topology_thread_siblings() return
a cpumask_t; these new ones return a (const) struct cpumask *.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
struct dentry is one of the most critical structures in the kernel. So it's
sad to see it going neglected.
With CONFIG_PROFILING turned on (which is probably the common case at least
for distros and kernel developers), sizeof(struct dcache) == 208 here
(64-bit). This gives 19 objects per slab.
I packed d_mounted into a hole, and took another 4 bytes off the inline
name length to take the padding out from the end of the structure. This
shinks it to 200 bytes. I could have gone the other way and increased the
length to 40, but I'm aiming for a magic number, read on...
I then got rid of the d_cookie pointer. This shrinks it to 192 bytes. Rant:
why was this ever a good idea? The cookie system should increase its hash
size or use a tree or something if lookups are a problem. Also the "fast
dcookie lookups" in oprofile should be moved into the dcookie code -- how
can oprofile possibly care about the dcookie_mutex? It gets dropped after
get_dcookie() returns so it can't be providing any sort of protection.
At 192 bytes, 21 objects fit into a 4K page, saving about 3MB on my system
with ~140 000 entries allocated. 192 is also a multiple of 64, so we get
nice cacheline alignment on 64 and 32 byte line systems -- any given dentry
will now require 3 cachelines to touch all fields wheras previously it
would require 4.
I know the inline name size was chosen quite carefully, however with the
reduction in cacheline footprint, it should actually be just about as fast
to do a name lookup for a 36 character name as it was before the patch (and
faster for other sizes). The memory footprint savings for names which are
<= 32 or > 36 bytes long should more than make up for the memory cost for
33-36 byte names.
Performance is a feature...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The only significant changes were to kvmppc_exit_timing_write() and
kvmppc_exit_timing_show(), both of which were dramatically simplified.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Existing KVM statistics are either just counters (kvm_stat) reported for
KVM generally or trace based aproaches like kvm_trace.
For KVM on powerpc we had the need to track the timings of the different exit
types. While this could be achieved parsing data created with a kvm_trace
extension this adds too much overhead (at least on embedded PowerPC) slowing
down the workloads we wanted to measure.
Therefore this patch adds a in-kernel exit timing statistic to the powerpc kvm
code. These statistic is available per vm&vcpu under the kvm debugfs directory.
As this statistic is low, but still some overhead it can be enabled via a
.config entry and should be off by default.
Since this patch touched all powerpc kvm_stat code anyway this code is now
merged and simplified together with the exit timing statistic code (still
working with exit timing disabled in .config).
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Store shadow TLB entries in memory, but only use it on host context switch
(instead of every guest entry). This improves performance for most workloads on
440 by reducing the guest TLB miss rate.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Formerly, we used to maintain a per-vcpu shadow TLB and on every entry to the
guest would load this array into the hardware TLB. This consumed 1280 bytes of
memory (64 entries of 16 bytes plus a struct page pointer each), and also
required some assembly to loop over the array on every entry.
Instead of saving a copy in memory, we can just store shadow mappings directly
into the hardware TLB, accepting that the host kernel will clobber these as
part of the normal 440 TLB round robin. When we do that we need less than half
the memory, and we have decreased the exit handling time for all guest exits,
at the cost of increased number of TLB misses because the host overwrites some
guest entries.
These savings will be increased on processors with larger TLBs or which
implement intelligent flush instructions like tlbivax (which will avoid the
need to walk arrays in software).
In addition to that and to the code simplification, we have a greater chance of
leaving other host userspace mappings in the TLB, instead of forcing all
subsequent tasks to re-fault all their mappings.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
KVM currently ignores the host's round robin TLB eviction selection, instead
maintaining its own TLB state and its own round robin index. However, by
participating in the normal 44x TLB selection, we can drop the alternate TLB
processing in KVM. This results in a significant performance improvement,
since that processing currently must be done on *every* guest exit.
Accordingly, KVM needs to be able to access and increment tlb_44x_index.
(KVM on 440 cannot be a module, so there is no need to export this symbol.)
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
KVM on 440 has always been able to handle large guest mappings with 4K host
pages -- we must, since the guest kernel uses 256MB mappings.
This patch makes KVM work when the host has large pages too (tested with 64K).
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
We used to defer invalidating userspace TLB entries until jumping out of the
kernel. This was causing MMU weirdness most easily triggered by using a pipe in
the guest, e.g. "dmesg | tail". I believe the problem was that after the guest
kernel changed the PID (part of context switch), the old process's mappings
were still present, and so copy_to_user() on the "return to new process" path
ended up using stale mappings.
Testing with large pages (64K) exposed the problem, probably because with 4K
pages, pressure on the TLB faulted all process A's mappings out before the
guest kernel could insert any for process B.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Bare metal Linux on 440 can "overmap" RAM in the kernel linear map, so that it
can use large (256MB) mappings even if memory isn't a multiple of 256MB. To
prevent the hardware prefetcher from loading from an invalid physical address
through that mapping, it's marked Guarded.
However, KVM must ensure that all guest mappings are backed by real physical
RAM (since a deliberate access through a guarded mapping could still cause a
machine check). Accordingly, we don't need to make our mappings guarded, so
let's allow prefetching as the designers intended.
Curiously this patch didn't affect performance at all on the quick test I
tried, but it's clearly the right thing to do anyways and may improve other
workloads.
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Kamalesh Babulal
Mohan Kumar M
Dave Liu
Stephen Rothwell
Matthias Fuchs
Paul Mackerras
Julia Lawall
Nathan Lynch
Michael Ellerman
Grant Likely
Dave Hansen
Nicolas Palix
Benjamin Herrenschmidt
Linus Torvalds
Bjorn Helgaas
Vitaly Bordug
Harvey Harrison
Masami Hiramatsu
Matthew Wilcox
Gary Hade
Mel Gorman
Nick Andrew
Frederik Schwarzer
Al Viro
Mike Travis
Rusty Russell
Nick Piggin
Avi Kivity
Hollis Blanchard