From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id 66A816B005C for ; Tue, 9 Jun 2009 02:48:17 -0400 (EDT) Date: Tue, 9 Jun 2009 16:13:30 +0900 From: Daisuke Nishimura Subject: [PATCH mmotm] vmscan: handle may_swap more strictly (Re: [PATCH mmotm] vmscan: fix may_swap handling for memcg) Message-Id: <20090609161330.fcd5facb.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20090608165457.fa8d17e6.nishimura@mxp.nes.nec.co.jp> References: <20090608121848.4370.A69D9226@jp.fujitsu.com> <20090608153916.3ccaeb9a.nishimura@mxp.nes.nec.co.jp> <20090608154634.437F.A69D9226@jp.fujitsu.com> <20090608165457.fa8d17e6.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: KOSAKI Motohiro Cc: LKML , linux-mm , Andrew Morton , Johannes Weiner , Balbir Singh , KAMEZAWA Hiroyuki , Daisuke Nishimura List-ID: > > and, too many recliaming pages is not only memcg issue. I don't think this > > patch provide generic solution. > > > Ah, you're right. It's not only memcg issue. > How about this one ? === From: Daisuke Nishimura Commit 2e2e425989080cc534fc0fca154cae515f971cf5 ("vmscan,memcg: reintroduce sc->may_swap) add may_swap flag and handle it at get_scan_ratio(). But the result of get_scan_ratio() is ignored when priority == 0, so anon lru is scanned even if may_swap == 0 or nr_swap_pages == 0. IMHO, this is not an expected behavior. As for memcg especially, because of this behavior many and many pages are swapped-out just in vain when oom is invoked by mem+swap limit. This patch is for handling may_swap flag more strictly. Signed-off-by: Daisuke Nishimura --- mm/vmscan.c | 18 +++++++++--------- 1 files changed, 9 insertions(+), 9 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 2ddcfc8..bacb092 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1407,13 +1407,6 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc, unsigned long ap, fp; struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); - /* If we have no swap space, do not bother scanning anon pages. */ - if (!sc->may_swap || (nr_swap_pages <= 0)) { - percent[0] = 0; - percent[1] = 100; - return; - } - anon = zone_nr_pages(zone, sc, LRU_ACTIVE_ANON) + zone_nr_pages(zone, sc, LRU_INACTIVE_ANON); file = zone_nr_pages(zone, sc, LRU_ACTIVE_FILE) + @@ -1511,15 +1504,22 @@ static void shrink_zone(int priority, struct zone *zone, enum lru_list l; unsigned long nr_reclaimed = sc->nr_reclaimed; unsigned long swap_cluster_max = sc->swap_cluster_max; + int noswap = 0; - get_scan_ratio(zone, sc, percent); + /* If we have no swap space, do not bother scanning anon pages. */ + if (!sc->may_swap || (nr_swap_pages <= 0)) { + noswap = 1; + percent[0] = 0; + percent[1] = 100; + } else + get_scan_ratio(zone, sc, percent); for_each_evictable_lru(l) { int file = is_file_lru(l); unsigned long scan; scan = zone_nr_pages(zone, sc, l); - if (priority) { + if (priority || noswap) { scan >>= priority; scan = (scan * percent[file]) / 100; } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org