From: David Rientjes <rientjes@google.com> To: Andrew Morton <akpm@linux-foundation.org>, Minchan Kim <minchan@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org>, Mel Gorman <mgorman@techsingularity.net>, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [patch v2] mm, vmscan: avoid thrashing anon lru when free + file is low Date: Mon, 1 May 2017 14:34:21 -0700 (PDT) [thread overview] Message-ID: <alpine.DEB.2.10.1705011432220.137835@chino.kir.corp.google.com> (raw) In-Reply-To: <20170420060904.GA3720@bbox> The purpose of the code that commit 623762517e23 ("revert 'mm: vmscan: do not swap anon pages just because free+file is low'") reintroduces is to prefer swapping anonymous memory rather than trashing the file lru. If the anonymous inactive lru for the set of eligible zones is considered low, however, or the length of the list for the given reclaim priority does not allow for effective anonymous-only reclaiming, then avoid forcing SCAN_ANON. Forcing SCAN_ANON will end up thrashing the small list and leave unreclaimed memory on the file lrus. If the inactive list is insufficient, fallback to balanced reclaim so the file lru doesn't remain untouched. Suggested-by: Minchan Kim <minchan@kernel.org> Signed-off-by: David Rientjes <rientjes@google.com> --- to akpm: this issue has been possible since at least 3.15, so it's probably not high priority for 4.12 but applies cleanly if it can sneak in mm/vmscan.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2204,8 +2204,17 @@ static void get_scan_count(struct lruvec *lruvec, struct mem_cgroup *memcg, } if (unlikely(pgdatfile + pgdatfree <= total_high_wmark)) { - scan_balance = SCAN_ANON; - goto out; + /* + * Force SCAN_ANON if there are enough inactive + * anonymous pages on the LRU in eligible zones. + * Otherwise, the small LRU gets thrashed. + */ + if (!inactive_list_is_low(lruvec, false, sc, false) && + lruvec_lru_size(lruvec, LRU_INACTIVE_ANON, sc->reclaim_idx) + >> sc->priority) { + scan_balance = SCAN_ANON; + goto out; + } } }
WARNING: multiple messages have this Message-ID (diff)
From: David Rientjes <rientjes@google.com> To: Andrew Morton <akpm@linux-foundation.org>, Minchan Kim <minchan@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org>, Mel Gorman <mgorman@techsingularity.net>, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [patch v2] mm, vmscan: avoid thrashing anon lru when free + file is low Date: Mon, 1 May 2017 14:34:21 -0700 (PDT) [thread overview] Message-ID: <alpine.DEB.2.10.1705011432220.137835@chino.kir.corp.google.com> (raw) In-Reply-To: <20170420060904.GA3720@bbox> The purpose of the code that commit 623762517e23 ("revert 'mm: vmscan: do not swap anon pages just because free+file is low'") reintroduces is to prefer swapping anonymous memory rather than trashing the file lru. If the anonymous inactive lru for the set of eligible zones is considered low, however, or the length of the list for the given reclaim priority does not allow for effective anonymous-only reclaiming, then avoid forcing SCAN_ANON. Forcing SCAN_ANON will end up thrashing the small list and leave unreclaimed memory on the file lrus. If the inactive list is insufficient, fallback to balanced reclaim so the file lru doesn't remain untouched. Suggested-by: Minchan Kim <minchan@kernel.org> Signed-off-by: David Rientjes <rientjes@google.com> --- to akpm: this issue has been possible since at least 3.15, so it's probably not high priority for 4.12 but applies cleanly if it can sneak in mm/vmscan.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2204,8 +2204,17 @@ static void get_scan_count(struct lruvec *lruvec, struct mem_cgroup *memcg, } if (unlikely(pgdatfile + pgdatfree <= total_high_wmark)) { - scan_balance = SCAN_ANON; - goto out; + /* + * Force SCAN_ANON if there are enough inactive + * anonymous pages on the LRU in eligible zones. + * Otherwise, the small LRU gets thrashed. + */ + if (!inactive_list_is_low(lruvec, false, sc, false) && + lruvec_lru_size(lruvec, LRU_INACTIVE_ANON, sc->reclaim_idx) + >> sc->priority) { + scan_balance = SCAN_ANON; + goto out; + } } } -- 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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-05-01 21:34 UTC|newest] Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-04-18 0:06 [patch] mm, vmscan: avoid thrashing anon lru when free + file is low David Rientjes 2017-04-18 0:06 ` David Rientjes 2017-04-18 1:36 ` Minchan Kim 2017-04-18 1:36 ` Minchan Kim 2017-04-18 21:32 ` David Rientjes 2017-04-18 21:32 ` David Rientjes 2017-04-19 0:14 ` Minchan Kim 2017-04-19 0:14 ` Minchan Kim 2017-04-19 23:24 ` David Rientjes 2017-04-19 23:24 ` David Rientjes 2017-04-20 6:09 ` Minchan Kim 2017-04-20 6:09 ` Minchan Kim 2017-05-01 21:34 ` David Rientjes [this message] 2017-05-01 21:34 ` [patch v2] " David Rientjes 2017-05-02 8:02 ` Michal Hocko 2017-05-02 8:02 ` Michal Hocko 2017-05-02 20:41 ` David Rientjes 2017-05-02 20:41 ` David Rientjes 2017-05-03 6:15 ` Michal Hocko 2017-05-03 6:15 ` Michal Hocko 2017-05-03 7:06 ` Michal Hocko 2017-05-03 7:06 ` Michal Hocko 2017-05-03 8:49 ` Michal Hocko 2017-05-03 8:49 ` Michal Hocko 2017-05-03 22:52 ` David Rientjes 2017-05-03 22:52 ` David Rientjes 2017-05-04 11:43 ` Michal Hocko 2017-05-04 11:43 ` Michal Hocko 2017-05-31 15:20 ` Michal Hocko 2017-05-31 15:20 ` Michal Hocko 2017-06-02 20:36 ` Andrew Morton 2017-06-02 20:36 ` Andrew Morton 2017-06-04 22:27 ` David Rientjes 2017-06-04 22:27 ` David Rientjes 2017-04-19 7:04 ` [patch] " Michal Hocko 2017-04-19 7:04 ` Michal Hocko 2017-04-18 7:11 ` Michal Hocko 2017-04-18 7:11 ` Michal Hocko
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=alpine.DEB.2.10.1705011432220.137835@chino.kir.corp.google.com \ --to=rientjes@google.com \ --cc=akpm@linux-foundation.org \ --cc=hannes@cmpxchg.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=mgorman@techsingularity.net \ --cc=minchan@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.