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| author | Johannes Weiner <hannes@cmpxchg.org> | 2017-05-04 00:55:03 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-04 01:52:11 +0300 |
| commit | 2a2e48854d704214dac7546e87ae0e4daa0e61a0 (patch) | |
| tree | a3b999e7be0b2495c9602348eda500a9908ae822 /include/linux/mmzone.h | |
| parent | 20ac28933c49433e0f064314de3618129b54a22e (diff) | |
| download | linux-2a2e48854d704214dac7546e87ae0e4daa0e61a0.tar.xz | |
mm: vmscan: fix IO/refault regression in cache workingset transition
Since commit 59dc76b0d4df ("mm: vmscan: reduce size of inactive file
list") we noticed bigger IO spikes during changes in cache access
patterns.
The patch in question shrunk the inactive list size to leave more room
for the current workingset in the presence of streaming IO. However,
workingset transitions that previously happened on the inactive list are
now pushed out of memory and incur more refaults to complete.
This patch disables active list protection when refaults are being
observed. This accelerates workingset transitions, and allows more of
the new set to establish itself from memory, without eating into the
ability to protect the established workingset during stable periods.
The workloads that were measurably affected for us were hit pretty bad
by it, with refault/majfault rates doubling and tripling during cache
transitions, and the machines sustaining half-hour periods of 100% IO
utilization, where they'd previously have sub-minute peaks at 60-90%.
Stateful services that handle user data tend to be more conservative
with kernel upgrades. As a result we hit most page cache issues with
some delay, as was the case here.
The severity seemed to warrant a stable tag.
Fixes: 59dc76b0d4df ("mm: vmscan: reduce size of inactive file list")
Link: http://lkml.kernel.org/r/20170404220052.27593-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mmzone.h')
| -rw-r--r-- | include/linux/mmzone.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 446cf68c1c09..e0c3c5e3d8a0 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -225,6 +225,8 @@ struct lruvec { struct zone_reclaim_stat reclaim_stat; /* Evictions & activations on the inactive file list */ atomic_long_t inactive_age; + /* Refaults at the time of last reclaim cycle */ + unsigned long refaults; #ifdef CONFIG_MEMCG struct pglist_data *pgdat; #endif |