The patch titled memcg: protect prev_priority has been added to the -mm tree. Its filename is memcg-protect-prev_priority.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: 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 -- 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