From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id E1AA66B0082 for ; Mon, 25 May 2009 23:18:37 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n4Q3IrrR032672 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Tue, 26 May 2009 12:18:53 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 35C9245DD72 for ; Tue, 26 May 2009 12:18:52 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id E2A3645DD75 for ; Tue, 26 May 2009 12:18:51 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id AEE14E08002 for ; Tue, 26 May 2009 12:18:51 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.249.87.106]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id CED90E18008 for ; Tue, 26 May 2009 12:18:50 +0900 (JST) Date: Tue, 26 May 2009 12:17:18 +0900 From: KAMEZAWA Hiroyuki Subject: [RFC][PATCH 4/5] memcg: fix swap account Message-Id: <20090526121718.8d68ea86.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090526121259.b91b3e9d.kamezawa.hiroyu@jp.fujitsu.com> References: <20090526121259.b91b3e9d.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" , "nishimura@mxp.nes.nec.co.jp" , "hugh.dickins@tiscali.co.uk" , "hannes@cmpxchg.org" , "linux-kernel@vger.kernel.org" List-ID: This patch fixes mis-accounting of swap usage in memcg. In current implementation, memcg's swap account is uncharged only when swap is completely freed. But there are several cases where swap cannot be freed cleanly. For handling that, this patch changes that memcg uncharges swap account when swap has no references other than cache. By this, memcg's swap entry accounting can be fully synchronous with the application's behavior. This patch also changes memcg's hooks for swap-out. (If delete_from_swap_cache() is called but there is no swap-reference, charge to swaps doesn't occur. (the charge for mem+swap is attached to the page itself if mapped) Signed-off-by: KAMEZAWA Hiroyuki --- include/linux/swap.h | 5 +++-- mm/memcontrol.c | 17 ++++++++++++----- mm/swapfile.c | 14 ++++++++++---- 3 files changed, 25 insertions(+), 11 deletions(-) Index: new-trial-swapcount/include/linux/swap.h =================================================================== --- new-trial-swapcount.orig/include/linux/swap.h +++ new-trial-swapcount/include/linux/swap.h @@ -340,10 +340,11 @@ static inline void disable_swap_token(vo } #ifdef CONFIG_CGROUP_MEM_RES_CTLR -extern void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent); +extern void +mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, int swapout); #else static inline void -mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) +mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, int swapout) { } #endif Index: new-trial-swapcount/mm/memcontrol.c =================================================================== --- new-trial-swapcount.orig/mm/memcontrol.c +++ new-trial-swapcount/mm/memcontrol.c @@ -189,6 +189,7 @@ enum charge_type { MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ + MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ NR_CHARGE_TYPE, }; @@ -1501,6 +1502,7 @@ __mem_cgroup_uncharge_common(struct page switch (ctype) { case MEM_CGROUP_CHARGE_TYPE_MAPPED: + case MEM_CGROUP_CHARGE_TYPE_DROP: if (page_mapped(page)) goto unlock_out; break; @@ -1564,18 +1566,23 @@ void mem_cgroup_uncharge_cache_page(stru * called after __delete_from_swap_cache() and drop "page" account. * memcg information is recorded to swap_cgroup of "ent" */ -void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) +void +mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, int swapout) { struct mem_cgroup *memcg; + int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; + + if (!swapout) /* this was a swap cache but the swap is unused ! */ + ctype = MEM_CGROUP_CHARGE_TYPE_DROP; + + memcg = __mem_cgroup_uncharge_common(page, ctype); - memcg = __mem_cgroup_uncharge_common(page, - MEM_CGROUP_CHARGE_TYPE_SWAPOUT); /* record memcg information */ - if (do_swap_account && memcg) { + if (do_swap_account && swapout && memcg) { swap_cgroup_record(ent, css_id(&memcg->css)); mem_cgroup_get(memcg); } - if (memcg) + if (swapout && memcg) css_put(&memcg->css); } #endif Index: new-trial-swapcount/mm/swapfile.c =================================================================== --- new-trial-swapcount.orig/mm/swapfile.c +++ new-trial-swapcount/mm/swapfile.c @@ -533,8 +533,9 @@ static int swap_entry_free(struct swap_i swap_list.next = p - swap_info; nr_swap_pages++; p->inuse_pages--; - mem_cgroup_uncharge_swap(ent); } + if (!swap_count(count)) + mem_cgroup_uncharge_swap(ent); if (swap_has_cache(count) && !swap_count(count)) { nr_cache_only_swaps++; p->cache_only++; @@ -564,12 +565,17 @@ void swap_free(swp_entry_t entry) void swapcache_free(swp_entry_t entry, struct page *page) { struct swap_info_struct *p; + int ret; - if (page) - mem_cgroup_uncharge_swapcache(page, entry); p = swap_info_get(entry); if (p) { - swap_entry_free(p, entry, 1); + ret = swap_entry_free(p, entry, 1); + if (page) { + if (ret) + mem_cgroup_uncharge_swapcache(page, entry, 1); + else + mem_cgroup_uncharge_swapcache(page, entry, 0); + } spin_unlock(&swap_lock); } return; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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