kernel: cgroup: push rcu read locking from css_is_ancestor() to callsite

Library functions should not grab locks when the callsites can do it,
even if the lock nests like the rcu read-side lock does.

Push the rcu_read_lock() from css_is_ancestor() to its single user,
mem_cgroup_same_or_subtree() in preparation for another user that may
already hold the rcu read-side lock.

Change-Id: I0ec7ec0059ed588d8f85bc9be8fdc42ce0ca7f5d
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Git-commit: 91c63734f6908425903aed69c04035592f18d398
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Revert "CHROMIUM: mm: Fix calculation of dirtyable memory"

This reverts commit e2cf9dd031f2db6a1d69d973a10bb444331a1142.
mm/page-writeback.c: fix dirty_balance_reserve subtraction from dirtyable memory

Tejun reported stuttering and latency spikes on a system where random
tasks would enter direct reclaim and get stuck on dirty pages.  Around
50% of memory was occupied by tmpfs backed by an SSD, and another disk
(rotating) was reading and writing at max speed to shrink a partition.

: The problem was pretty ridiculous.  It's a 8gig machine w/ one ssd and 10k
: rpm harddrive and I could reliably reproduce constant stuttering every
: several seconds for as long as buffered IO was going on on the hard drive
: either with tmpfs occupying somewhere above 4gig or a test program which
: allocates about the same amount of anon memory.  Although swap usage was
: zero, turning off swap also made the problem go away too.
:
: The trigger conditions seem quite plausible - high anon memory usage w/
: heavy buffered IO and swap configured - and it's highly likely that this
: is happening in the wild too.  (this can happen with copying large files
: to usb sticks too, right?)

This patch (of 2):

The dirty_balance_reserve is an approximation of the fraction of free
pages that the page allocator does not make available for page cache
allocations.  As a result, it has to be taken into account when
calculating the amount of "dirtyable memory", the baseline to which
dirty_background_ratio and dirty_ratio are applied.

However, currently the reserve is subtracted from the sum of free and
reclaimable pages, which is non-sensical and leads to erroneous results
when the system is dominated by unreclaimable pages and the
dirty_balance_reserve is bigger than free+reclaimable.  In that case, at
least the already allocated cache should be considered dirtyable.

Fix the calculation by subtracting the reserve from the amount of free
pages, then adding the reclaimable pages on top.

[akpm@linux-foundation.org: fix CONFIG_HIGHMEM build]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Tejun Heo <tj@kernel.org>
Tested-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
mm/hotplug: correctly setup fallback zonelists when creating new pgdat

When hotadd_new_pgdat() is called to create new pgdat for a new node, a
fallback zonelist should be created for the new node.  There's code to try
to achieve that in hotadd_new_pgdat() as below:

	/*
	 * The node we allocated has no zone fallback lists. For avoiding
	 * to access not-initialized zonelist, build here.
	 */
	mutex_lock(&zonelists_mutex);
	build_all_zonelists(pgdat, NULL);
	mutex_unlock(&zonelists_mutex);

But it doesn't work as expected.  When hotadd_new_pgdat() is called, the
new node is still in offline state because node_set_online(nid) hasn't
been called yet.  And build_all_zonelists() only builds zonelists for
online nodes as:

        for_each_online_node(nid) {
                pg_data_t *pgdat = NODE_DATA(nid);

                build_zonelists(pgdat);
                build_zonelist_cache(pgdat);
        }

Though we hope to create zonelist for the new pgdat, but it doesn't.  So
add a new parameter "pgdat" the build_all_zonelists() to build pgdat for
the new pgdat too.

Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Keping Chen <chenkeping@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ZRAM/ZSMALLOC: initial file import from Linux 3.14 rc1 source

Signed-off-by: Paul Reioux <reioux@gmail.com>

Conflicts:
	drivers/staging/Kconfig
	drivers/staging/Makefile
zsmalloc: add copyright

Add my copyright to the zsmalloc source code which I maintain.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ZRAM/ZSMALLOC: Linux 3.4 API backport

Signed-off-by: Paul Reioux <reioux@gmail.com>
trace: memkill: trace LMK and OOM kills

How to enable tracer:

  # mount -t debugfs nodev /sys/kernel/debug
  # echo 1 > /sys/kernel/debug/tracing/tracing_on
  # echo 1 > /sys/kernel/debug/tracing/events/memkill/enable
  # cat /sys/kernel/debug/tracing/trace

Event format:

  oom_kill: <pid> <comm> <total_vm> <anon_rss> <file_rss> <oom_score_adj> <order> <points> <cached> <freeswap>
  oom_kill_shared: <pid> <comm>
  lmk_kill: <pid> <comm> <selected_oom_adj> <selected_tasksize> <min_adj> <cached> <freeswap>

Change-Id: Ic45e181c62aead9b19d2a40363217f9220896096
Signed-off-by: Jeffrey Carlyle <jeff.carlyle@motorola.com>
Reviewed-on: http://gerrit.pcs.mot.com/480746
Reviewed-on: http://gerrit.pcs.mot.com/513174
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Jason Hrycay <jason.hrycay@motorola.com>
Reviewed-by: Klocwork kwcheck <klocwork-kwcheck@sourceforge.mot.com>
Reviewed-by: Thirumarai Selvi S <a16462@motorola.com>
Reviewed-by: Check Patch <CHEKPACH@motorola.com>
Reviewed-by: Christopher Fries <qcf001@motorola.com>
Submit-Approved: Jira Key <jirakey@motorola.com>
(cherry picked from commit ef733ddfbb73cd33daf36720fa474ce4c8acb1f7)
trace: allow memkill tracing to be selectively enabled

Change-Id: I8a50d6b121192b0dc94e2a9a0e05246a47045e81
Signed-off-by: Jeffrey Carlyle <jeff.carlyle@motorola.com>
Reviewed-on: http://gerrit.pcs.mot.com/482673
Reviewed-on: http://gerrit.pcs.mot.com/513906
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Klocwork kwcheck <klocwork-kwcheck@sourceforge.mot.com>
Reviewed-by: Thirumarai Selvi S <a16462@motorola.com>
Reviewed-by: Check Patch <CHEKPACH@motorola.com>
Submit-Approved: Jira Key <jirakey@motorola.com>
(cherry picked from commit fd9bd32cd8f005b0d2f6438935fdd0bc9654c938)

Conflicts:
	drivers/staging/android/lowmemorykiller.c
staging: android: lowmemorykiller: implement task's adj rbtree

Based on the current LMK implementation, LMK has to scan all processes to
select the correct task to kill during low memory.
The basic idea for the optimization is to :
queue all tasks with oom_score_adj priority, and then LMK just selects the
proper task from the queue(rbtree) to kill.

performance improvement:
the current implementation: average time to find a task to kill : 1004us
the optimized implementation: average time to find a task to kill: 43us

Change-Id: I4dbbdd5673314dbbdabb71c3eff0dc229ce4ea91
Signed-off-by: Hong-Mei Li <a21834@motorola.com>
Reviewed-on: http://gerrit.pcs.mot.com/548917
SLT-Approved: Slta Waiver <sltawvr@motorola.com>
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Yi-Wei Zhao <gbjc64@motorola.com>
Submit-Approved: Jira Key <jirakey@motorola.com>
set version to 1.55