From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id BBFAB6B003D for ; Thu, 26 Mar 2009 21:40:03 -0400 (EDT) Date: Fri, 27 Mar 2009 10:39:11 +0900 From: Daisuke Nishimura Subject: [BUGFIX][PATCH] memcg: fix shrink_usage Message-Id: <20090327103911.4fd1b61f.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20090326153803.23689561.nishimura@mxp.nes.nec.co.jp> References: <20090326130821.40c26cf1.nishimura@mxp.nes.nec.co.jp> <20090326141246.32305fe5.kamezawa.hiroyu@jp.fujitsu.com> <20090326145148.ba722e1e.nishimura@mxp.nes.nec.co.jp> <20090326150613.09aacf0d.kamezawa.hiroyu@jp.fujitsu.com> <20090326151733.1e36bf43.nishimura@mxp.nes.nec.co.jp> <20090326152734.365b8689.kamezawa.hiroyu@jp.fujitsu.com> <20090326153803.23689561.nishimura@mxp.nes.nec.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: linux-mm Cc: KAMEZAWA Hiroyuki , Balbir Singh , Li Zefan , Hugh Dickins , Daisuke Nishimura List-ID: > > Could you write a patch in this direction ? (or I'll write by myself.) > > It's obvious that you do better test. > > > Okey. > > I'll make a patch and repost it after doing some tests for review. > This is the updated one. I've confirmed that this can prevent an invalid OOM. === From: Daisuke Nishimura Current mem_cgroup_shrink_usage has two problems. 1. It doesn't call mem_cgroup_out_of_memory and doesn't update last_oom_jiffies, so pagefault_out_of_memory invokes global OOM. 2. Considering hierarchy, shrinking has to be done from the mem_over_limit, not from the memcg which the page would be charged to. mem_cgroup_try_charge_swapin does all of these works properly, so we use it and call cancel_charge_swapin when it succeeded. The name of "shrink_usage" is not appropriate for this purpose, so we change it too. Signed-off-by: Daisuke Nishimura --- include/linux/memcontrol.h | 4 ++-- mm/memcontrol.c | 33 ++++++++++++--------------------- mm/shmem.c | 8 ++++++-- 3 files changed, 20 insertions(+), 25 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 18146c9..928b714 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -56,7 +56,7 @@ extern void mem_cgroup_move_lists(struct page *page, enum lru_list from, enum lru_list to); extern void mem_cgroup_uncharge_page(struct page *page); extern void mem_cgroup_uncharge_cache_page(struct page *page); -extern int mem_cgroup_shrink_usage(struct page *page, +extern int mem_cgroup_shmem_charge_fallback(struct page *page, struct mm_struct *mm, gfp_t gfp_mask); extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, @@ -155,7 +155,7 @@ static inline void mem_cgroup_uncharge_cache_page(struct page *page) { } -static inline int mem_cgroup_shrink_usage(struct page *page, +static inline int mem_cgroup_shmem_charge_fallback(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) { return 0; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 3492286..3b88e7f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1664,37 +1664,28 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem, } /* - * A call to try to shrink memory usage under specified resource controller. - * This is typically used for page reclaiming for shmem for reducing side - * effect of page allocation from shmem, which is used by some mem_cgroup. + * A call to try to shrink memory usage on charge failure at shmem's swapin. + * Calling hierarchical_reclaim is not enough because we should update + * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM. + * Moreover considering hierarchy, we should reclaim from the mem_over_limit, + * not from the memcg which this page would be charged to. + * try_charge_swapin does all of these works properly. */ -int mem_cgroup_shrink_usage(struct page *page, +int mem_cgroup_shmem_charge_fallback(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) { struct mem_cgroup *mem = NULL; - int progress = 0; - int retry = MEM_CGROUP_RECLAIM_RETRIES; + int ret; if (mem_cgroup_disabled()) return 0; - if (page) - mem = try_get_mem_cgroup_from_swapcache(page); - if (!mem && mm) - mem = try_get_mem_cgroup_from_mm(mm); - if (unlikely(!mem)) - return 0; - do { - progress = mem_cgroup_hierarchical_reclaim(mem, - gfp_mask, true, false); - progress += mem_cgroup_check_under_limit(mem); - } while (!progress && --retry); + ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem); + if (!ret) + mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */ - css_put(&mem->css); - if (!retry) - return -ENOMEM; - return 0; + return ret; } static DEFINE_MUTEX(set_limit_mutex); diff --git a/mm/shmem.c b/mm/shmem.c index a5a30fd..ce99098 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1326,8 +1326,12 @@ repeat: shmem_swp_unmap(entry); spin_unlock(&info->lock); if (error == -ENOMEM) { - /* allow reclaim from this memory cgroup */ - error = mem_cgroup_shrink_usage(swappage, + /* + * reclaim from proper memory cgroup and + * call memcg's OOM if needed. + */ + error = mem_cgroup_shmem_charge_fallback( + swappage, current->mm, gfp); if (error) { -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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