In massive parallel enviroment, res_counter can be a performance
bottleneck. One strong techinque to reduce lock contention is reducing
calls by coalescing some amount of calls into one.
Considering charge/uncharge chatacteristic,
- charge is done one by one via demand-paging.
- uncharge is done by
- in chunk at munmap, truncate, exit, execve...
- one by one via vmscan/paging.
It seems we have a chance to coalesce uncharges for improving scalability
at unmap/truncation.
This patch is a for coalescing uncharge. For avoiding scattering memcg's
structure to functions under /mm, this patch adds memcg batch uncharge
information to the task. A reason for per-task batching is for making use
of caller's context information. We do batched uncharge (deleyed
uncharge) when truncation/unmap occurs but do direct uncharge when
uncharge is called by memory reclaim (vmscan.c).
The degree of coalescing depends on callers
- at invalidate/trucate... pagevec size
- at unmap ....ZAP_BLOCK_SIZE
(memory itself will be freed in this degree.)
Then, we'll not coalescing too much.
On x86-64 8cpu server, I tested overheads of memcg at page fault by
running a program which does map/fault/unmap in a loop. Running
a task per a cpu by taskset and see sum of the number of page faults
in 60secs.
[without memcg config]
40156968 page-faults # 0.085 M/sec ( +- 0.046% )
27.67 cache-miss/faults
[root cgroup]
36659599 page-faults # 0.077 M/sec ( +- 0.247% )
31.58 miss/faults
[in a child cgroup]
18444157 page-faults # 0.039 M/sec ( +- 0.133% )
69.96 miss/faults
[child with this patch]
27133719 page-faults # 0.057 M/sec ( +- 0.155% )
47.16 miss/faults
We can see some amounts of improvement.
(root cgroup doesn't affected by this patch)
Another patch for "charge" will follow this and above will be improved more.
Changelog(since 2009/10/02):
- renamed filed of memcg_batch (as pages to bytes, memsw to memsw_bytes)
- some clean up and commentary/description updates.
- added initialize code to copy_process(). (possible bug fix)
Changelog(old):
- fixed !CONFIG_MEM_CGROUP case.
- rebased onto the latest mmotm + softlimit fix patches.
- unified patch for callers
- added commetns.
- make ->do_batch as bool.
- removed css_get() at el. We don't need it.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
/proc/fs/reiserfs/version is on the way of removing ->read_proc interface.
It's empty however, so simply remove it instead of doing dummy
conversion. It's hard to see what information userspace can extract from
empty file.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a helper function to enable raster. Also add one member in the
private data structure to track the current blank status, another function
pointer which takes in the platform specific callback function to control
panel power.
These updates will help in adding suspend/resume and frame buffer blank
operation features.
Signed-off-by: Chaithrika U S <chaithrika@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch provides the acceleration entry points for the SM501
framebuffer driver.
This patch provides the sync, copyarea and fillrect entry points, using
the SM501's 2D acceleration engine to perform the operations in-chip
rather than across the bus.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Simtec Linux Team <linux@simtec.co.uk>
Signed-off-by: Vincent Sanders <vince@simtec.co.uk>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Drivers may use gpiolib sysfs as part of their public user space
interface. The GPIO number and polarity might change from board to
board. The gpio_export_link() call can be used to hide the GPIO number
from user space. Add support for also hiding the GPIO line polarity
changes from user space.
Signed-off-by: Jani Nikula <ext-jani.1.nikula@nokia.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix node-oriented allocation handling in oom-kill.c I myself think of this
as a bugfix not as an ehnancement.
In these days, things are changed as
- alloc_pages() eats nodemask as its arguments, __alloc_pages_nodemask().
- mempolicy don't maintain its own private zonelists.
(And cpuset doesn't use nodemask for __alloc_pages_nodemask())
So, current oom-killer's check function is wrong.
This patch does
- check nodemask, if nodemask && nodemask doesn't cover all
node_states[N_HIGH_MEMORY], this is CONSTRAINT_MEMORY_POLICY.
- Scan all zonelist under nodemask, if it hits cpuset's wall
this faiulre is from cpuset.
And
- modifies the caller of out_of_memory not to call oom if __GFP_THISNODE.
This doesn't change "current" behavior. If callers use __GFP_THISNODE
it should handle "page allocation failure" by itself.
- handle __GFP_NOFAIL+__GFP_THISNODE path.
This is something like a FIXME but this gfpmask is not used now.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (80 commits)
dm snapshot: use merge origin if snapshot invalid
dm snapshot: report merge failure in status
dm snapshot: merge consecutive chunks together
dm snapshot: trigger exceptions in remaining snapshots during merge
dm snapshot: delay merging a chunk until writes to it complete
dm snapshot: queue writes to chunks being merged
dm snapshot: add merging
dm snapshot: permit only one merge at once
dm snapshot: support barriers in snapshot merge target
dm snapshot: avoid allocating exceptions in merge
dm snapshot: rework writing to origin
dm snapshot: add merge target
dm exception store: add merge specific methods
dm snapshot: create function for chunk_is_tracked wait
dm snapshot: make bio optional in __origin_write
dm mpath: reject messages when device is suspended
dm: export suspended state to targets
dm: rename dm_suspended to dm_suspended_md
dm: swap target postsuspend call and setting suspended flag
dm crypt: add plain64 iv
...
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (26 commits)
clockevents: Convert to raw_spinlock
clockevents: Make tick_device_lock static
debugobjects: Convert to raw_spinlocks
perf_event: Convert to raw_spinlock
hrtimers: Convert to raw_spinlocks
genirq: Convert irq_desc.lock to raw_spinlock
smp: Convert smplocks to raw_spinlocks
rtmutes: Convert rtmutex.lock to raw_spinlock
sched: Convert pi_lock to raw_spinlock
sched: Convert cpupri lock to raw_spinlock
sched: Convert rt_runtime_lock to raw_spinlock
sched: Convert rq->lock to raw_spinlock
plist: Make plist debugging raw_spinlock aware
bkl: Fixup core_lock fallout
locking: Cleanup the name space completely
locking: Further name space cleanups
alpha: Fix fallout from locking changes
locking: Implement new raw_spinlock
locking: Convert raw_rwlock functions to arch_rwlock
locking: Convert raw_rwlock to arch_rwlock
...
* git://git.infradead.org/battery-2.6:
power_supply_sysfs: Handle -ENODATA in a special way
wm831x_backup: Remove unused variables
gta02: Set pcf50633 charger_reference_current_ma
pcf50633: Query charger status directly
pcf50633: Properly reenable charging when the supply conditions change
pcf50633: Get rid of charging restart software auto-triggering
pcf50633: introduces battery charging current control
pcf50633: Add ac power supply class to the charger
wm831x: Factor out WM831x backup battery charger
Implement selftest feature as specified by chip manufacturer. Control:
read selftest sysfs entry
Response: "OK x y z" or "FAIL x y z"
where x, y, and z are difference between selftest mode and normal mode.
Test is passed when values are within acceptance limit values.
Acceptance limits are provided via platform data. See chip spesifications
for acceptance limits. If limits are not properly set, OK / FAIL decision
is meaningless. However, userspace application can still make decision
based on the numeric x, y, z values.
Selftest is meant for HW diagnostic purposes. It is not meant to be
called during normal use of the chip. It may cause false interrupt
events. Selftest mode delays polling of the normal results but it doesn't
cause wrong values. Chip must be in static state during selftest. Any
acceration during the test causes most probably failure.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Éric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow the use of another DMA controller driver in atmel-mci sd/mmc driver.
This adds a generic dma_slave pointer to the mci platform structure where
we can store DMA controller information. In atmel-mci we use information
provided by this structure to initialize the driver (with new helper
functions that are architecture dependant).
This also adds at32/avr32 chip modifications to cope with this new access
method.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recently, We marked strstrip() as must_check. because it was frequently
misused and it should be checked. However, we found one exception.
scsi/ipr.c intentionally ignore return value of strstrip. Because it
wishes to keep the whitespace at the beginning.
Thus we need to keep with and without checked whitespace trim function.
This patch adds a new strim() and changes ipr.c to use it.
[akpm@linux-foundation.org: coding-style fixes]
Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On the following sentence:
while (*s && isspace(*s))
s++;
If *s == 0, isspace() evaluates to ((_ctype[*s] & 0x20) != 0), which
evaluates to ((0x08 & 0x20) != 0) which equals to 0 as well.
If *s == 1, we depend on isspace() result anyway. In other words,
"a char equals zero is never a space", so remove this check.
Also, *s != 0 is most common case (non-null string).
Fixed const return as noticed by Jan Engelhardt and James Bottomley.
Fixed unnecessary extra cast on strstrip() as noticed by Jan Engelhardt.
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel offers with TIOCL_GETKMSGREDIRECT ioctl() the possibility to
redirect the kernel messages to a specific console.
However, since it's not possible to switch to the kernel message console
after a panic(), it would be nice if the kernel would print the panic
message on the current console.
This patch series adds a new interface to access the global kmsg_redirect
variable by a function to be able to use it in code where
CONFIG_VT_CONSOLE is not set (kernel/panic.c).
This patch:
Instead of using and exporting a global value kmsg_redirect, introduce a
function vt_kmsg_redirect() that both can set and return the console where
messages are printed.
Change all users of kmsg_redirect (the VT code itself and kernel/power.c)
to the new interface.
The main advantage is that vt_kmsg_redirect() can also be used when
CONFIG_VT_CONSOLE is not set.
Signed-off-by: Bernhard Walle <bernhard@bwalle.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is based on the old code on arch/x86/kernel/mfgpt_32.c, except it's
not x86 specific, it's modular, and it makes use of a PCI BAR rather than
a random MSR. Currently module unloading is not supported; it's uncertain
whether or not it can be made work with the hardware.
[akpm@linux-foundation.org: add X86 dependency]
Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
Cc: Jordan Crouse <jordan@cosmicpenguin.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Chris Ball <cjb@laptop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This creates a CS5535/CS5536 GPIO driver which uses a gpio_chip backend
(allowing GPIO users to use the generic GPIO API if desired) while also
allowing architecture-specific users directly (via the cs5535_gpio_*
functions).
Tested on an OLPC machine. Some Leemotes also use CS5536 (with a mips
cpu), which is why this is in drivers/gpio rather than arch/x86.
Currently, it conflicts with older geode GPIO support; once MFGPT support
is reworked to also be more generic, the older geode code will be removed.
Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jordan Crouse <jordan@cosmicpenguin.net>
Cc: David Brownell <david-b@pacbell.net>
Reviewed-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are quite a few instances in the kernel of checks of pointers both
against NULL and against the errno range, handling both cases identically.
This additional helper function would simplify such code.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
