The patch titled
Subject: mm, vmscan: make zone_reclaimable_pages more precise
has been added to the -mm tree. Its filename is
mm-vmscan-make-zone_reclaimable_pages-more-precise.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-vmscan-make-zone_reclaimable_pages-more-precise.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-vmscan-make-zone_reclaimable_pages-more-precise.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Michal Hocko <mhocko@xxxxxxxx>
Subject: mm, vmscan: make zone_reclaimable_pages more precise
zone_reclaimable_pages() is used in should_reclaim_retry() which uses it
to calculate the target for the watermark check. This means that precise
numbers are important for the correct decision. zone_reclaimable_pages
uses zone_page_state which can contain stale data with per-cpu diffs not
synced yet (the last vmstat_update might have run 1s in the past).
Use zone_page_state_snapshot() in zone_reclaimable_pages() instead. None
of the current callers is in a hot path where getting the precise value
(which involves per-cpu iteration) would cause an unreasonable overhead.
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Suggested-by: David Rientjes <rientjes@xxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Acked-by: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff -puN mm/vmscan.c~mm-vmscan-make-zone_reclaimable_pages-more-precise mm/vmscan.c
--- a/mm/vmscan.c~mm-vmscan-make-zone_reclaimable_pages-more-precise
+++ a/mm/vmscan.c
@@ -195,21 +195,21 @@ static unsigned long zone_reclaimable_pa
{
unsigned long nr;
- nr = zone_page_state(zone, NR_ACTIVE_FILE) +
- zone_page_state(zone, NR_INACTIVE_FILE) +
- zone_page_state(zone, NR_ISOLATED_FILE);
+ nr = zone_page_state_snapshot(zone, NR_ACTIVE_FILE) +
+ zone_page_state_snapshot(zone, NR_INACTIVE_FILE) +
+ zone_page_state_snapshot(zone, NR_ISOLATED_FILE);
if (get_nr_swap_pages() > 0)
- nr += zone_page_state(zone, NR_ACTIVE_ANON) +
- zone_page_state(zone, NR_INACTIVE_ANON) +
- zone_page_state(zone, NR_ISOLATED_ANON);
+ nr += zone_page_state_snapshot(zone, NR_ACTIVE_ANON) +
+ zone_page_state_snapshot(zone, NR_INACTIVE_ANON) +
+ zone_page_state_snapshot(zone, NR_ISOLATED_ANON);
return nr;
}
bool zone_reclaimable(struct zone *zone)
{
- return zone_page_state(zone, NR_PAGES_SCANNED) <
+ return zone_page_state_snapshot(zone, NR_PAGES_SCANNED) <
zone_reclaimable_pages(zone) * 6;
}
_
Patches currently in -mm which might be from mhocko@xxxxxxxx are
mm-vmstat-make-quiet_vmstat-lighter.patch
vmstat-make-vmstat_update-deferrable.patch
mm-vmscan-make-zone_reclaimable_pages-more-precise.patch
mm-oom-rework-oom-detection.patch
mm-throttle-on-io-only-when-there-are-too-many-dirty-and-writeback-pages.patch
mm-use-watermak-checks-for-__gfp_repeat-high-order-allocations.patch
mm-oom-introduce-oom-reaper.patch
mm-oom-introduce-oom-reaper-v4.patch
oom-reaper-handle-anonymous-mlocked-pages.patch
oom-clear-tif_memdie-after-oom_reaper-managed-to-unmap-the-address-space.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
