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| author | Mel Gorman <mgorman@techsingularity.net> | 2016-07-29 00:47:17 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-29 01:07:41 +0200 |
| commit | 7ee36a14f06cc937f6b2c2932c2e48f590970581 (patch) | |
| tree | 367c9779d4f12bb4b15bbda8fd2a35fa400efc71 /mm/memcontrol.c | |
| parent | mm: show node_pages_scanned per node, not zone (diff) | |
| download | linux-7ee36a14f06cc937f6b2c2932c2e48f590970581.tar.xz linux-7ee36a14f06cc937f6b2c2932c2e48f590970581.zip | |
mm, vmscan: Update all zone LRU sizes before updating memcg
Minchan Kim reported setting the following warning on a 32-bit system
although it can affect 64-bit systems.
WARNING: CPU: 4 PID: 1322 at mm/memcontrol.c:998 mem_cgroup_update_lru_size+0x103/0x110
mem_cgroup_update_lru_size(f44b4000, 1, -7): zid 1 lru_size 1 but empty
Modules linked in:
CPU: 4 PID: 1322 Comm: cp Not tainted 4.7.0-rc4-mm1+ #143
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0x76/0xaf
__warn+0xea/0x110
? mem_cgroup_update_lru_size+0x103/0x110
warn_slowpath_fmt+0x3b/0x40
mem_cgroup_update_lru_size+0x103/0x110
isolate_lru_pages.isra.61+0x2e2/0x360
shrink_active_list+0xac/0x2a0
? __delay+0xe/0x10
shrink_node_memcg+0x53c/0x7a0
shrink_node+0xab/0x2a0
do_try_to_free_pages+0xc6/0x390
try_to_free_pages+0x245/0x590
LRU list contents and counts are updated separately. Counts are updated
before pages are added to the LRU and updated after pages are removed.
The warning above is from a check in mem_cgroup_update_lru_size that
ensures that list sizes of zero are empty.
The problem is that node-lru needs to account for highmem pages if
CONFIG_HIGHMEM is set. One impact of the implementation is that the
sizes are updated in multiple passes when pages from multiple zones were
isolated. This happens whether HIGHMEM is set or not. When multiple
zones are isolated, it's possible for a debugging check in memcg to be
tripped.
This patch forces all the zone counts to be updated before the memcg
function is called.
Link: http://lkml.kernel.org/r/1468588165-12461-6-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: Minchan Kim <minchan@kernel.org>
Reported-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9cbd40ebccd1..13be30c3ea78 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -965,7 +965,6 @@ out: * mem_cgroup_update_lru_size - account for adding or removing an lru page * @lruvec: mem_cgroup per zone lru vector * @lru: index of lru list the page is sitting on - * @zid: Zone ID of the zone pages have been added to * @nr_pages: positive when adding or negative when removing * * This function must be called under lru_lock, just before a page is added @@ -973,15 +972,13 @@ out: * so as to allow it to check that lru_size 0 is consistent with list_empty). */ void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru, - enum zone_type zid, int nr_pages) + int nr_pages) { struct mem_cgroup_per_node *mz; unsigned long *lru_size; long size; bool empty; - __update_lru_size(lruvec, lru, zid, nr_pages); - if (mem_cgroup_disabled()) return; |