The patch titled
vmscan: clip swap_cluster_max in shrink_all_memory()
has been added to the -mm tree. Its filename is
vmscan-clip-swap_cluster_max-in-shrink_all_memory.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 ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: vmscan: clip swap_cluster_max in shrink_all_memory()
From: Johannes Weiner <hannes@xxxxxxxxxxx>
shrink_inactive_list() scans in sc->swap_cluster_max chunks until it hits
the scan limit it was passed.
shrink_inactive_list()
{
do {
isolate_pages(swap_cluster_max)
shrink_page_list()
} while (nr_scanned < max_scan);
}
This assumes that swap_cluster_max is not bigger than the scan limit
because the latter is checked only after at least one iteration.
In shrink_all_memory() sc->swap_cluster_max is initialized to the overall
reclaim goal in the beginning but not decreased while reclaim is making
progress which leads to subsequent calls to shrink_inactive_list()
reclaiming way too much in the one iteration that is done unconditionally.
Set sc->swap_cluster_max always to the proper goal before doing
shrink_all_zones()
shrink_list()
shrink_inactive_list().
While the current shrink_all_memory() happily reclaims more than actually
requested, this patch fixes it to never exceed the goal:
unpatched
wanted=10000 reclaimed=13356
wanted=10000 reclaimed=19711
wanted=10000 reclaimed=10289
wanted=10000 reclaimed=17306
wanted=10000 reclaimed=10700
wanted=10000 reclaimed=10004
wanted=10000 reclaimed=13301
wanted=10000 reclaimed=10976
wanted=10000 reclaimed=10605
wanted=10000 reclaimed=10088
wanted=10000 reclaimed=15000
patched
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=9599
wanted=10000 reclaimed=8476
wanted=10000 reclaimed=8326
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=9919
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=9624
wanted=10000 reclaimed=10000
wanted=10000 reclaimed=10000
wanted=8500 reclaimed=8092
wanted=316 reclaimed=316
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reviewed-by: MinChan Kim <minchan.kim@xxxxxxxxx>
Acked-by: Nigel Cunningham <ncunningham@xxxxxxxxxxx>
Acked-by: "Rafael J. Wysocki" <rjw@xxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/vmscan.c~vmscan-clip-swap_cluster_max-in-shrink_all_memory mm/vmscan.c
--- a/mm/vmscan.c~vmscan-clip-swap_cluster_max-in-shrink_all_memory
+++ a/mm/vmscan.c
@@ -2107,7 +2107,6 @@ unsigned long shrink_all_memory(unsigned
struct scan_control sc = {
.gfp_mask = GFP_KERNEL,
.may_unmap = 0,
- .swap_cluster_max = nr_pages,
.may_writepage = 1,
.isolate_pages = isolate_pages_global,
};
@@ -2149,6 +2148,7 @@ unsigned long shrink_all_memory(unsigned
unsigned long nr_to_scan = nr_pages - sc.nr_reclaimed;
sc.nr_scanned = 0;
+ sc.swap_cluster_max = nr_to_scan;
shrink_all_zones(nr_to_scan, prio, pass, &sc);
if (sc.nr_reclaimed >= nr_pages)
goto out;
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
origin.patch
linux-next.patch
swsusp-clean-up-shrink_all_zones.patch
swsusp-dont-fiddle-with-swappiness.patch
vmscan-rename-scmay_swap-to-may_unmap.patch
mm-introduce-for_each_populated_zone-macro.patch
mm-introduce-for_each_populated_zone-macro-cleanup.patch
mm-shrink_all_memory-use-scnr_reclaimed.patch
mm-shrink_all_memory-use-scnr_reclaimed-checkpatch-fixes.patch
vmscan-clip-swap_cluster_max-in-shrink_all_memory.patch
memcg-remove-mem_cgroup_calc_mapped_ratio-take2.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
