Subject: + mm-memcg-iteration-skip-memcgs-not-yet-fully-initialized.patch added to -mm tree To: hughd@xxxxxxxxxx,hannes@xxxxxxxxxxx,mhocko@xxxxxxx,tj@xxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Tue, 14 Jan 2014 16:15:46 -0800 The patch titled Subject: mm/memcg: iteration skip memcgs not yet fully initialized has been added to the -mm tree. Its filename is mm-memcg-iteration-skip-memcgs-not-yet-fully-initialized.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-memcg-iteration-skip-memcgs-not-yet-fully-initialized.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-memcg-iteration-skip-memcgs-not-yet-fully-initialized.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: Hugh Dickins <hughd@xxxxxxxxxx> Subject: mm/memcg: iteration skip memcgs not yet fully initialized It is surprising that the mem_cgroup iterator can return memcgs which have not yet been fully initialized. By accident (or trial and error?) this appears not to present an actual problem; but it may be better to prevent such surprises, by skipping memcgs not yet online. Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff -puN mm/memcontrol.c~mm-memcg-iteration-skip-memcgs-not-yet-fully-initialized mm/memcontrol.c --- a/mm/memcontrol.c~mm-memcg-iteration-skip-memcgs-not-yet-fully-initialized +++ a/mm/memcontrol.c @@ -1078,10 +1078,8 @@ skip_node: * protected by css_get and the tree walk is rcu safe. */ if (next_css) { - struct mem_cgroup *mem = mem_cgroup_from_css(next_css); - - if (css_tryget(&mem->css)) - return mem; + if ((next_css->flags & CSS_ONLINE) && css_tryget(next_css)) + return mem_cgroup_from_css(next_css); else { prev_css = next_css; goto skip_node; _ Patches currently in -mm which might be from hughd@xxxxxxxxxx are mm-remove-bug_on-from-mlock_vma_page.patch fsnotify-do-not-share-events-between-notification-groups-fix.patch mm-call-mmu-notifiers-when-copying-a-hugetlb-page-range.patch mm-rmap-recompute-pgoff-for-huge-page.patch mm-rmap-factor-nonlinear-handling-out-of-try_to_unmap_file.patch mm-rmap-factor-lock-function-out-of-rmap_walk_anon.patch mm-rmap-make-rmap_walk-to-get-the-rmap_walk_control-argument.patch mm-rmap-extend-rmap_walk_xxx-to-cope-with-different-cases.patch mm-rmap-use-rmap_walk-in-try_to_unmap.patch mm-rmap-use-rmap_walk-in-try_to_munlock.patch mm-rmap-use-rmap_walk-in-page_referenced.patch mm-rmap-use-rmap_walk-in-page_referenced-fix.patch mm-rmap-use-rmap_walk-in-page_mkclean.patch mm-documentation-remove-hopelessly-out-of-date-locking-doc.patch mm-munlock-fix-potential-race-with-thp-page-split.patch mm-swap-fix-race-on-swap_info-reuse-between-swapoff-and-swapon.patch mm-swap-fix-race-on-swap_info-reuse-between-swapoff-and-swapon-fix.patch mm-memcg-fix-last_dead_count-memory-wastage.patch mm-memcg-iteration-skip-memcgs-not-yet-fully-initialized.patch swap-add-a-simple-detector-for-inappropriate-swapin-readahead.patch linux-next.patch zsmalloc-move-it-under-mm.patch zram-promote-zram-from-staging.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