From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f41.google.com (mail-wm0-f41.google.com [74.125.82.41]) by kanga.kvack.org (Postfix) with ESMTP id 3D0316B025E for ; Tue, 12 Apr 2016 05:14:28 -0400 (EDT) Received: by mail-wm0-f41.google.com with SMTP id a140so45127407wma.0 for ; Tue, 12 Apr 2016 02:14:28 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id s3si22839961wmf.48.2016.04.12.02.14.27 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 12 Apr 2016 02:14:27 -0700 (PDT) Subject: Re: mmotm woes, mainly compaction References: <570CB9CE.1070408@suse.cz> From: Vlastimil Babka Message-ID: <570CBC72.9020003@suse.cz> Date: Tue, 12 Apr 2016 11:14:26 +0200 MIME-Version: 1.0 In-Reply-To: <570CB9CE.1070408@suse.cz> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins , Michal Hocko , Andrew Morton Cc: Michal Hocko , linux-kernel@vger.kernel.org, linux-mm@kvack.org On 04/12/2016 11:03 AM, Vlastimil Babka wrote: > On 04/12/2016 09:18 AM, Hugh Dickins wrote: >> 3. /proc/sys/vm/stat_refresh warns nr_isolated_anon and nr_isolated_file >> go increasingly negative under compaction: which would add delay when >> should be none, or no delay when should delay. putback_movable_pages() >> decrements the NR_ISOLATED counts which acct_isolated() increments, >> so isolate_migratepages_block() needs to acct before putback in that >> special case, and isolate_migratepages_range() can always do the acct >> itself, leaving migratepages putback to caller like most other places. > > The isolate_migratepages_block() part is mmotm-specific, so I'll split > it out in this patch. Thanks for catching it and the lack of reset for > cc->nr_migratepages which wasn't mentioned in changelog so I added it. > >> 5. It's easier to track the life of cc->migratepages if we don't assign >> it to a migratelist variable. > > This is also included here. > > This is a -fix for: > mm-compaction-skip-blocks-where-isolation-fails-in-async-direct-compaction.patch > > ----8<---- > From 59a0075b6cf85045aa2dc5cee1f27797bcd0b3d2 Mon Sep 17 00:00:00 2001 > From: Hugh Dickins > Date: Tue, 12 Apr 2016 10:51:20 +0200 > Subject: [PATCH] mm, compaction: prevent nr_isolated_* from going negative > > /proc/sys/vm/stat_refresh warns nr_isolated_anon and nr_isolated_file > go increasingly negative under compaction: which would add delay when > should be none, or no delay when should delay. putback_movable_pages() > decrements the NR_ISOLATED counts which acct_isolated() increments, > so isolate_migratepages_block() needs to acct before putback in that > special case. It's also useful to reset cc->nr_migratepages after putback > so we don't needlessly return too early on the COMPACT_CLUSTER_MAX check. > > Also it's easier to track the life of cc->migratepages if we don't assign > it to a migratelist variable. Forgot Signed-off-by: Vlastimil Babka > --- > mm/compaction.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 67f886ecd773..ab649fba3d88 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -638,7 +638,6 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, > { > struct zone *zone = cc->zone; > unsigned long nr_scanned = 0, nr_isolated = 0; > - struct list_head *migratelist = &cc->migratepages; > struct lruvec *lruvec; > unsigned long flags = 0; > bool locked = false; > @@ -817,7 +816,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, > del_page_from_lru_list(page, lruvec, page_lru(page)); > > isolate_success: > - list_add(&page->lru, migratelist); > + list_add(&page->lru, &cc->migratepages); > cc->nr_migratepages++; > nr_isolated++; > > @@ -851,9 +850,11 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, > spin_unlock_irqrestore(&zone->lru_lock, flags); > locked = false; > } > - putback_movable_pages(migratelist); > - nr_isolated = 0; > + acct_isolated(zone, cc); > + putback_movable_pages(&cc->migratepages); > + cc->nr_migratepages = 0; > cc->last_migrated_pfn = 0; > + nr_isolated = 0; > } > > if (low_pfn < next_skip_pfn) { > -- 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