The patch titled
memcg: protect prev_priority
has been added to the -mm tree. Its filename is
memcg-protect-prev_priority.patch
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------------------------------------------------------
Subject: memcg: protect prev_priority
From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Currently, mem_cgroup doesn't have own lock and almost its member doesn't
need. (e.g. mem_cgroup->info is protected by zone lock, mem_cgroup->stat
is per cpu variable)
However, there is one explict exception. mem_cgroup->prev_priorit need
lock, but doesn't protect. Luckly, this is NOT bug because prev_priority
isn't used for current reclaim code.
However, we plan to use prev_priority future again. Therefore, fixing is
better.
In addition, we plan to reuse this lock for another member. Then
"reclaim_param_lock" name is better than "prev_priority_lock".
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Cc: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff -puN mm/memcontrol.c~memcg-protect-prev_priority mm/memcontrol.c
--- a/mm/memcontrol.c~memcg-protect-prev_priority
+++ a/mm/memcontrol.c
@@ -144,6 +144,11 @@ struct mem_cgroup {
*/
struct mem_cgroup_lru_info info;
+ /*
+ protect against reclaim related member.
+ */
+ spinlock_t reclaim_param_lock;
+
int prev_priority; /* for recording reclaim priority */
/*
@@ -400,18 +405,28 @@ int mem_cgroup_calc_mapped_ratio(struct
*/
int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
{
- return mem->prev_priority;
+ int prev_priority;
+
+ spin_lock(&mem->reclaim_param_lock);
+ prev_priority = mem->prev_priority;
+ spin_unlock(&mem->reclaim_param_lock);
+
+ return prev_priority;
}
void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
{
+ spin_lock(&mem->reclaim_param_lock);
if (priority < mem->prev_priority)
mem->prev_priority = priority;
+ spin_unlock(&mem->reclaim_param_lock);
}
void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
{
+ spin_lock(&mem->reclaim_param_lock);
mem->prev_priority = priority;
+ spin_unlock(&mem->reclaim_param_lock);
}
int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone)
@@ -2070,6 +2085,7 @@ mem_cgroup_create(struct cgroup_subsys *
}
mem_cgroup_set_inactive_ratio(mem);
mem->last_scanned_child = NULL;
+ spin_lock_init(&mem->reclaim_param_lock);
return &mem->css;
free_out:
_
Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are
vmscan-evict-streaming-io-first.patch
linux-next.patch
arch-ia64-kernel-iosapicc-fix-warnings.patch
mm-report-the-pagesize-backing-a-vma-in-proc-pid-smaps.patch
mm-report-the-mmu-pagesize-in-proc-pid-smaps.patch
oom-fix-zone_scan_mutex-name.patch
mm-get-rid-of-pagevec_release_nonlru.patch
cleanup-get-rid-of-ifdef-config_migration.patch
mm-more-likely-reclaim-madv_sequential-mappings.patch
mm-make-page_lock_anon_vma-static.patch
memcg-reclaim-shouldnt-change-zone-recent_rotated-statistics.patch
mm-make-init_section_page_cgroup-static.patch
mm-make-maddr-__iomem.patch
mm-make-mem_cgroup_resize_limit-static.patch
mm-make-scan_all_zones_unevictable_pages-static.patch
mm-make-scan_zone_unevictable_pages-static.patch
mm-make-setup_per_zone_inactive_ratio-static.patch
mm-make-vread-and-vwrite-declaration.patch
vmscan-bail-out-of-direct-reclaim-after-swap_cluster_max-pages.patch
mm-kill-zone_is_near_oom.patch
softirq-introduce-statistics-for-softirq.patch
proc-export-statistics-for-softirq-to-proc.patch
proc-update-document-for-proc-softirqs-and-proc-stat.patch
memcg-new-force_empty-to-free-pages-under-group-fix.patch
memcg-new-force_empty-to-free-pages-under-group-fix-fix.patch
memcg-revert-gfp-mask-fix.patch
memcg-check-group-leader-fix.patch
memcg-memoryswap-controller-fix-limit-check.patch
memcg-swapout-refcnt-fix.patch
memcg-hierarchy-avoid-unnecessary-reclaim.patch
inactive_anon_is_low-move-to-vmscan.patch
mm-introduce-zone_reclaim-struct.patch
mm-add-zone-nr_pages-helper-function.patch
mm-make-get_scan_ratio-safe-for-memcg.patch
memcg-add-null-check-to-page_cgroup_zoneinfo.patch
memcg-add-inactive_anon_is_low.patch
memcg-add-mem_cgroup_zone_nr_pages.patch
memcg-add-zone_reclaim_stat.patch
memcg-remove-mem_cgroup_cal_reclaim.patch
memcg-show-reclaim-stat.patch
memcg-rename-scan-global-lru.patch
memcg-protect-prev_priority.patch
memcg-swappiness.patch
memcg-explain-details-and-test-document.patch
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