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KAMEZAWA Hiroyuki 4b91355e9d memcg: fix/change behavior of shared anon at moving task 
This patch changes memcg's behavior at task_move().

At task_move(), the kernel scans a task's page table and move the changes
for mapped pages from source cgroup to target cgroup.  There has been a
bug at handling shared anonymous pages for a long time.

Before patch:
  - The spec says 'shared anonymous pages are not moved.'
  - The implementation was 'shared anonymoys pages may be moved'.
    If page_mapcount <=2, shared anonymous pages's charge were moved.

After patch:
  - The spec says 'all anonymous pages are moved'.
  - The implementation is 'all anonymous pages are moved'.

Considering usage of memcg, this will not affect user's experience.
'shared anonymous' pages only exists between a tree of processes which
don't do exec().  Moving one of process without exec() seems not sane.
For example, libcgroup will not be affected by this change.  (Anyway, no
one noticed the implementation for a long time...)

Below is a discussion log:

 - current spec/implementation are complex
 - Now, shared file caches are moved
 - It adds unclear check as page_mapcount(). To do correct check,
   we should check swap users, etc.
 - No one notice this implementation behavior. So, no one get benefit
   from the design.
 - In general, once task is moved to a cgroup for running, it will not
   be moved....
 - Finally, we have control knob as memory.move_charge_at_immigrate.

Here is a patch to allow moving shared pages, completely. This makes
memcg simpler and fix current broken code.

Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
..
ABI MFD changes for 3.5 2012-05-29 11:53:11 -07:00
accounting
acpi Update documentation for parameter *notrigger* in einj.txt 2012-03-30 03:30:19 -04:00
aoe Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
arm arm-soc: soc specific changes, part 2 2012-05-26 13:05:55 -07:00
auxdisplay
backlight backlight: new backlight driver for LP855x devices 2012-03-23 16:58:33 -07:00
blackfin Documentation: Fix typo in multiple files in Documentation 2012-04-16 14:37:13 +02:00
block Documentation: drop as block elevator reference in switching-sched.txt 2011-11-04 12:01:48 -07:00
blockdev Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
cdrom doc: fix broken references 2011-09-27 18:08:04 +02:00
cgroups memcg: fix/change behavior of shared anon at moving task 2012-05-29 16:22:24 -07:00
connector
console
cpu-freq Doc: cpufreq: Fix typo and outdated line 2011-11-08 10:23:29 +01:00
cpuidle cpuidle: add a sysfs entry to disable specific C state for debug purpose. 2012-03-30 01:52:58 -04:00
cris CRIS: Update documentation 2012-04-03 13:09:18 +02:00
crypto
development-process Documentation: Update stable address 2011-12-12 14:14:31 -08:00
device-mapper dm: add verity target 2012-03-28 18:43:38 +01:00
devicetree MFD changes for 3.5 2012-05-29 11:53:11 -07:00
DocBook Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-05-24 10:21:51 -07:00
driver-model Pin control subsystem changes for kernel 3.5: 2012-05-21 16:58:23 -07:00
dvb Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-05-24 10:21:51 -07:00
early-userspace
EDID drm: allow loading an EDID as firmware to override broken monitor 2012-03-20 10:09:28 +00:00
extcon Documentation/extcon: porting guide for Android kernel switch driver. 2012-04-20 09:24:27 -07:00
fault-injection fault-injection: update documentation with the mmc module param 2011-10-26 16:32:13 -04:00
fb Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
filesystems mm: document the meminfo and vmstat fields of relevance to transparent hugepages 2012-05-29 16:22:23 -07:00
firmware_class
frv doc: fix broken references 2011-09-27 18:08:04 +02:00
hid
hwmon hwmon updates for 3.5-rc1 2012-05-23 14:15:09 -07:00
i2c i2c: Rename last mux driver to standard pattern 2012-05-12 14:28:18 +02:00
i2o Documentation: Fix multiple typo in Documentation 2012-03-07 16:08:24 +01:00
ia64
ide Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
infiniband
input Documentation: input.txt: clarify mousedev 'cat' command syntax 2012-03-30 16:03:15 -07:00
ioctl mei: update Documentation/ioctl/ioctl-number.txt 2012-05-09 14:00:31 -07:00
isdn Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
ja_JP
kbuild Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2012-05-28 10:37:56 -07:00
kdump [S390] Add s390x description to Documentation/kdump/kdump.txt 2011-12-27 11:27:13 +01:00
ko_KR driver-core: documentation: fix up Greg's email address 2012-02-15 14:48:01 -08:00
laptops Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
leds drivers/leds/leds-lp5521.c: support led pattern data 2012-03-23 16:58:34 -07:00
m68k Documentation: add pointer to name_to_dev_t for root= values 2011-08-03 14:25:21 -10:00
make
memory-devices memory: emif: add basic infrastructure for EMIF driver 2012-05-02 00:10:49 -07:00
mips
misc-devices mei: Documentation: add generated example binary into .gitignore file 2012-05-14 15:43:44 -07:00
mmc mmc: core: Fixup delayed work clock gating patch 2012-01-11 23:58:43 -05:00
mn10300
mtd
namespaces
netlabel
networking Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-05-22 19:22:50 -07:00
nfc NFC: Update Documentation/nfc-hci.txt 2012-05-15 17:28:01 -04:00
parisc Documentation: Fix typo in multiple files in Documentation 2012-04-16 14:37:13 +02:00
PCI doc: fix broken references 2011-09-27 18:08:04 +02:00
pcmcia
power Power management updates for 3.5 2012-05-23 14:07:06 -07:00
powerpc Revert "powerpc/hw-breakpoint: Use generic hw-breakpoint interfaces for new PPC ptrace flags" 2012-05-22 14:37:24 +10:00
pps
prctl Documentation: prctl/seccomp_filter 2012-04-14 11:13:22 +10:00
pti
ptp
rapidio RapidIO: documentation update 2011-11-02 16:07:02 -07:00
RCU rcu: Introduce rcutorture testing for rcu_barrier() 2012-04-30 10:48:18 -07:00
s390 Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
scheduler sched: Remove stale power aware scheduling remnants and dysfunctional knobs 2012-05-17 13:48:56 +02:00
scsi Merge branch 'delete-mca' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2012-05-23 17:12:06 -07:00
security Smack: allow for significantly longer Smack labels v4 2012-05-14 22:48:38 -07:00
serial serial: delete the MCA specific 8250 support. 2012-05-17 19:02:14 -04:00
sh
sound Sound updates for 3.5-rc1 2012-05-23 13:05:43 -07:00
spi spi: create a message queueing infrastructure 2012-03-07 19:19:48 -07:00
sysctl net: doc: merge /proc/sys/net/core/* documents into one place 2012-04-27 00:09:26 -04:00
target Documentation: Fix typo in tcm_mod_builder.py 2012-02-10 09:52:18 +01:00
telephony
thermal thermal: Rename generate_netlink_event 2012-01-23 03:15:25 -05:00
timers doc: fix broken references 2011-09-27 18:08:04 +02:00
trace tracing: Fix kconfig warning due to a typo 2012-05-08 14:17:25 +02:00
usb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-05-22 19:22:50 -07:00
vDSO
video4linux Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-05-24 10:21:51 -07:00
virtual Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
vm mm: document the meminfo and vmstat fields of relevance to transparent hugepages 2012-05-29 16:22:23 -07:00
w1
watchdog Documentation/watchdog: Fix the file descriptor leak when no cmdline arg given 2012-05-23 16:27:48 +02:00
wimax
x86 x86-64, doc: Remove int 0xcc from entry_64.S documentation 2011-08-16 08:04:08 -07:00
zh_CN Fix a mistake sentence in the file 'Documentation/zh_CN/magic-number.txt' 2012-05-07 17:20:27 -07:00
.gitignore
00-INDEX MCA: delete all remaining traces of microchannel bus support. 2012-05-17 19:06:13 -04:00
applying-patches.txt
atomic_ops.txt doc: Add load/store guarantees to Documentation/atomic-ops.txt 2011-12-11 10:31:58 -08:00
bad_memory.txt
basic_profiling.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt doc: fix broken references 2011-09-27 18:08:04 +02:00
cachetlb.txt
Changes
circular-buffers.txt
clk.txt Documentation: common clk API 2012-03-16 20:35:01 +00:00
coccinelle.txt coccinelle.txt: update documentation to include M= option 2012-01-14 22:25:56 +01:00
CodingStyle Documentation: CodingStyle: add inline assembly guidelines 2012-03-30 16:03:15 -07:00
cpu-hotplug.txt documentation: remove references to cpu_*_map. 2012-03-29 15:38:31 +10:30
cpu-load.txt
cputopology.txt
crc32.txt crc32: move long comment about crc32 fundamentals to Documentation/ 2012-03-23 16:58:37 -07:00
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt
devices.txt Merge branch 'delete-mca' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2012-05-23 17:12:06 -07:00
digsig.txt crypto: digital signature verification support 2011-11-09 12:10:37 +02:00
DMA-API-HOWTO.txt
DMA-API.txt include/linux/dma-mapping.h: add dma_zalloc_coherent() 2011-11-02 16:07:02 -07:00
DMA-attributes.txt common: DMA-mapping: add NON-CONSISTENT attribute 2012-03-28 16:36:44 +02:00
dma-buf-sharing.txt dma-buf: add initial vmap documentation 2012-05-25 12:51:11 +05:30
DMA-ISA-LPC.txt
dmaengine.txt Documentation: Fix multiple typo in Documentation 2012-03-07 16:08:24 +01:00
dontdiff Documentation: remove 'mach' from dontdiff file 2012-03-30 16:03:15 -07:00
dynamic-debug-howto.txt dynamic_debug: update Documentation/*, Kconfig.debug 2012-04-30 16:26:30 -04:00
edac.txt Documentation: Fix typo in multiple files in Documentation 2012-04-16 14:37:13 +02:00
eisa.txt MCA: delete all remaining traces of microchannel bus support. 2012-05-17 19:06:13 -04:00
email-clients.txt Documentation: email-clients: Add better Thunderbird information 2011-08-13 18:34:03 -07:00
feature-removal-schedule.txt MMC highlights for 3.5: 2012-05-25 08:23:32 -07:00
flexible-arrays.txt
futex-requeue-pi.txt
gcov.txt
gpio.txt gpio: add flags to export GPIOs when requesting 2012-04-05 21:24:06 -07:00
highuid.txt
HOWTO docs: update HOWTO for 2.6.x -> 3.x versioning 2012-04-19 19:13:08 -07:00
hw_random.txt
hwspinlock.txt hwspinlock/core: register a bank of hwspinlocks in a single API call 2011-09-21 19:45:34 +03:00
init.txt
initrd.txt Documentation/initrd.txt: Change the location of util-linux 2012-05-25 16:18:34 +02:00
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt irq_domain: add documentation and MAINTAINERS entry. 2012-02-14 14:06:47 -07:00
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt
kernel-docs.txt doc: fix broken references 2011-09-27 18:08:04 +02:00
kernel-parameters.txt Merge branch 'doc' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-05-28 10:40:11 -07:00
kmemcheck.txt
kmemleak.txt kmemleak: Handle percpu memory allocation 2011-12-02 16:12:42 +00:00
kobject.txt driver-core: documentation: fix up Greg's email address 2012-02-15 14:48:01 -08:00
kprobes.txt
kref.txt
ldm.txt
local_ops.txt
lockdep-design.txt lockdep: Update documentation for lock-class leak detection 2011-12-11 10:31:23 -08:00
lockstat.txt
lockup-watchdogs.txt watchdog: Update documentation 2012-02-11 15:11:28 +01:00
logo.gif
logo.txt
magic-number.txt drivers/net: fix up stale paths from driver reorg 2012-01-30 12:54:40 -05:00
Makefile mei: move doc files Documentation/misc-devices/mei 2012-05-09 13:59:09 -07:00
ManagementStyle
md.txt md: create externally visible flags for supporting hot-replace. 2011-12-23 10:17:51 +11:00
media-framework.txt [media] media: Add link_validate() op to check links to the sink pad 2012-05-14 08:44:11 -03:00
memory-barriers.txt doc: fix broken references 2011-09-27 18:08:04 +02:00
memory-hotplug.txt Documentation: Fix typo in multiple files in Documentation 2012-04-16 14:37:13 +02:00
memory.txt
mono.txt Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
mutex-design.txt
nommu-mmap.txt
numastat.txt Doc: Update numastat.txt 2012-02-28 16:05:06 +01:00
oops-tracing.txt module,bug: Add TAINT_OOT_MODULE flag for modules not built in-tree 2011-11-07 07:54:42 +10:30
padata.txt
parport-lowlevel.txt
parport.txt Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
pi-futex.txt
pinctrl.txt pinctrl: implement devm_pinctrl_get()/put() 2012-04-18 13:53:13 +02:00
pnp.txt
preempt-locking.txt
printk-formats.txt
prio_tree.txt
ramoops.txt pstore/ram: Add ECC support 2012-05-17 08:51:59 -07:00
rbtree.txt
remoteproc.txt remoteproc: remove the single rpmsg vdev limitation 2012-03-06 19:14:12 +02:00
rfkill.txt doc: fix broken references 2011-09-27 18:08:04 +02:00
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt rpmsg: add virtio-based remote processor messaging bus 2012-02-08 22:53:58 +02:00
rt-mutex-design.txt
rt-mutex.txt
rtc.txt
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
SM501.txt
sparse.txt
spinlocks.txt
stable_api_nonsense.txt
stable_kernel_rules.txt stable: update documentation to ask for kernel version 2012-01-24 10:50:22 -08:00
static-keys.txt Documentation: Fix typo in multiple files in Documentation 2012-04-16 14:37:13 +02:00
SubmitChecklist
SubmittingDrivers Documentation: SubmittingDrivers: fix Linus's git tree URL 2011-08-13 18:34:03 -07:00
SubmittingPatches Documentation/SubmittingPatches: suggested the use of scripts/get_maintainer.pl 2012-05-25 16:18:30 +02:00
svga.txt
sysfs-rules.txt
sysrq.txt Documentation: sysrq: Crutcher Dunnavant is unavailable 2012-03-30 16:03:15 -07:00
unaligned-memory-access.txt
unicode.txt
unshare.txt
VGA-softcursor.txt
vgaarbiter.txt misc latin1 to utf8 conversions 2012-01-02 13:04:55 +01:00
video-output.txt
vme_api.txt VME: Move API documentation to Documentation folder 2012-05-08 16:01:34 -07:00
volatile-considered-harmful.txt
workqueue.txt
xz.txt
zorro.txt