From: Vlastimil Babka <vbabka@suse.cz> To: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org>, Mel Gorman <mgorman@techsingularity.net>, Joonsoo Kim <iamjoonsoo.kim@lge.com>, David Rientjes <rientjes@google.com>, Rik van Riel <riel@redhat.com>, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vlastimil Babka <vbabka@suse.cz> Subject: [PATCH v6 06/11] mm, compaction: more reliably increase direct compaction priority Date: Wed, 10 Aug 2016 11:12:21 +0200 [thread overview] Message-ID: <20160810091226.6709-7-vbabka@suse.cz> (raw) In-Reply-To: <20160810091226.6709-1-vbabka@suse.cz> During reclaim/compaction loop, compaction priority can be increased by the should_compact_retry() function, but the current code is not optimal. Priority is only increased when compaction_failed() is true, which means that compaction has scanned the whole zone. This may not happen even after multiple attempts with a lower priority due to parallel activity, so we might needlessly struggle on the lower priorities and possibly run out of compaction retry attempts in the process. After this patch we are guaranteed at least one attempt at the highest compaction priority even if we exhaust all retries at the lower priorities. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> --- mm/page_alloc.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index fb975cec3518..b28517b918b0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3155,13 +3155,8 @@ should_compact_retry(struct alloc_context *ac, int order, int alloc_flags, * so it doesn't really make much sense to retry except when the * failure could be caused by insufficient priority */ - if (compaction_failed(compact_result)) { - if (*compact_priority > MIN_COMPACT_PRIORITY) { - (*compact_priority)--; - return true; - } - return false; - } + if (compaction_failed(compact_result)) + goto check_priority; /* * make sure the compaction wasn't deferred or didn't bail out early @@ -3185,6 +3180,15 @@ should_compact_retry(struct alloc_context *ac, int order, int alloc_flags, if (compaction_retries <= max_retries) return true; + /* + * Make sure there is at least one attempt at the highest priority + * if we exhausted all retries at the lower priorities + */ +check_priority: + if (*compact_priority > MIN_COMPACT_PRIORITY) { + (*compact_priority)--; + return true; + } return false; } #else -- 2.9.2
WARNING: multiple messages have this Message-ID (diff)
From: Vlastimil Babka <vbabka@suse.cz> To: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org>, Mel Gorman <mgorman@techsingularity.net>, Joonsoo Kim <iamjoonsoo.kim@lge.com>, David Rientjes <rientjes@google.com>, Rik van Riel <riel@redhat.com>, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vlastimil Babka <vbabka@suse.cz> Subject: [PATCH v6 06/11] mm, compaction: more reliably increase direct compaction priority Date: Wed, 10 Aug 2016 11:12:21 +0200 [thread overview] Message-ID: <20160810091226.6709-7-vbabka@suse.cz> (raw) In-Reply-To: <20160810091226.6709-1-vbabka@suse.cz> During reclaim/compaction loop, compaction priority can be increased by the should_compact_retry() function, but the current code is not optimal. Priority is only increased when compaction_failed() is true, which means that compaction has scanned the whole zone. This may not happen even after multiple attempts with a lower priority due to parallel activity, so we might needlessly struggle on the lower priorities and possibly run out of compaction retry attempts in the process. After this patch we are guaranteed at least one attempt at the highest compaction priority even if we exhaust all retries at the lower priorities. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> --- mm/page_alloc.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index fb975cec3518..b28517b918b0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3155,13 +3155,8 @@ should_compact_retry(struct alloc_context *ac, int order, int alloc_flags, * so it doesn't really make much sense to retry except when the * failure could be caused by insufficient priority */ - if (compaction_failed(compact_result)) { - if (*compact_priority > MIN_COMPACT_PRIORITY) { - (*compact_priority)--; - return true; - } - return false; - } + if (compaction_failed(compact_result)) + goto check_priority; /* * make sure the compaction wasn't deferred or didn't bail out early @@ -3185,6 +3180,15 @@ should_compact_retry(struct alloc_context *ac, int order, int alloc_flags, if (compaction_retries <= max_retries) return true; + /* + * Make sure there is at least one attempt at the highest priority + * if we exhausted all retries at the lower priorities + */ +check_priority: + if (*compact_priority > MIN_COMPACT_PRIORITY) { + (*compact_priority)--; + return true; + } return false; } #else -- 2.9.2 -- 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:[~2016-08-10 20:42 UTC|newest] Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-08-10 9:12 [PATCH v6 00/11] make direct compaction more deterministic Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka 2016-08-10 9:12 ` [PATCH v6 01/11] mm, compaction: make whole_zone flag ignore cached scanner positions Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka 2016-08-10 9:12 ` [PATCH v6 02/11] mm, compaction: cleanup unused functions Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka 2016-08-10 9:12 ` [PATCH v6 03/11] mm, compaction: rename COMPACT_PARTIAL to COMPACT_SUCCESS Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka 2016-08-18 9:01 ` Michal Hocko 2016-08-18 9:01 ` Michal Hocko 2016-08-10 9:12 ` [PATCH v6 04/11] mm, compaction: don't recheck watermarks after COMPACT_SUCCESS Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka 2016-08-16 6:12 ` Joonsoo Kim 2016-08-16 6:12 ` Joonsoo Kim 2016-08-16 6:11 ` Vlastimil Babka 2016-08-16 6:11 ` Vlastimil Babka 2016-08-18 11:59 ` Vlastimil Babka 2016-08-18 11:59 ` Vlastimil Babka 2016-08-18 9:03 ` Michal Hocko 2016-08-18 9:03 ` Michal Hocko 2016-08-10 9:12 ` [PATCH v6 05/11] mm, compaction: add the ultimate direct compaction priority Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka 2016-08-16 5:58 ` Joonsoo Kim 2016-08-16 5:58 ` Joonsoo Kim 2016-08-18 12:23 ` Vlastimil Babka 2016-08-18 12:23 ` Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka [this message] 2016-08-10 9:12 ` [PATCH v6 06/11] mm, compaction: more reliably increase " Vlastimil Babka 2016-08-16 6:07 ` Joonsoo Kim 2016-08-16 6:07 ` Joonsoo Kim 2016-08-16 6:31 ` Vlastimil Babka 2016-08-16 6:31 ` Vlastimil Babka 2016-08-18 9:10 ` Michal Hocko 2016-08-18 9:10 ` Michal Hocko 2016-08-18 9:44 ` Vlastimil Babka 2016-08-18 9:44 ` Vlastimil Babka 2016-08-18 9:48 ` Michal Hocko 2016-08-18 9:48 ` Michal Hocko 2016-08-10 9:12 ` [PATCH v6 07/11] mm, compaction: use correct watermark when checking compaction success Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka 2016-08-10 9:12 ` [PATCH v6 08/11] mm, compaction: create compact_gap wrapper Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka 2016-08-16 6:15 ` Joonsoo Kim 2016-08-16 6:15 ` Joonsoo Kim 2016-08-16 6:15 ` Vlastimil Babka 2016-08-16 6:15 ` Vlastimil Babka 2016-08-16 6:41 ` Joonsoo Kim 2016-08-16 6:41 ` Joonsoo Kim 2016-08-18 12:13 ` Vlastimil Babka 2016-08-18 12:13 ` Vlastimil Babka 2016-08-10 9:12 ` [PATCH v6 09/11] mm, compaction: use proper alloc_flags in __compaction_suitable() Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka 2016-08-10 9:12 ` [PATCH v6 10/11] mm, compaction: require only min watermarks for non-costly orders Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka 2016-08-16 6:16 ` Joonsoo Kim 2016-08-16 6:16 ` Joonsoo Kim 2016-08-16 6:36 ` Vlastimil Babka 2016-08-16 6:36 ` Vlastimil Babka 2016-08-16 6:46 ` Joonsoo Kim 2016-08-16 6:46 ` Joonsoo Kim 2016-08-18 12:20 ` Vlastimil Babka 2016-08-18 12:20 ` Vlastimil Babka 2016-08-10 9:12 ` [PATCH v6 11/11] mm, vmscan: make compaction_ready() more accurate and readable Vlastimil Babka 2016-08-10 9:12 ` Vlastimil Babka
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=20160810091226.6709-7-vbabka@suse.cz \ --to=vbabka@suse.cz \ --cc=akpm@linux-foundation.org \ --cc=iamjoonsoo.kim@lge.com \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=mgorman@techsingularity.net \ --cc=mhocko@kernel.org \ --cc=riel@redhat.com \ --cc=rientjes@google.com \ /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.