From: Vlastimil Babka <vbabka@suse.cz> To: Michal Hocko <mhocko@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>, Ralf-Peter Rohbeck <Ralf-Peter.Rohbeck@quantum.com>, Olaf Hering <olaf@aepfle.de> Cc: linux-kernel@vger.kernel.org, Linus Torvalds <torvalds@linux-foundation.org>, linux-mm@kvack.org, Vlastimil Babka <vbabka@suse.cz>, Mel Gorman <mgorman@techsingularity.net>, Joonsoo Kim <iamjoonsoo.kim@lge.com>, David Rientjes <rientjes@google.com>, Rik van Riel <riel@redhat.com>, Michal Hocko <mhocko@suse.com> Subject: [PATCH 2/4] mm, compaction: more reliably increase direct compaction priority Date: Tue, 6 Sep 2016 15:52:56 +0200 [thread overview] Message-ID: <20160906135258.18335-3-vbabka@suse.cz> (raw) In-Reply-To: <20160906135258.18335-1-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> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> --- 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 1df7694f4ec7..f8bed910e3cf 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3174,13 +3174,8 @@ 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 @@ -3204,6 +3199,15 @@ 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 -- 2.9.3
WARNING: multiple messages have this Message-ID (diff)
From: Vlastimil Babka <vbabka@suse.cz> To: Michal Hocko <mhocko@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>, Ralf-Peter Rohbeck <Ralf-Peter.Rohbeck@quantum.com>, Olaf Hering <olaf@aepfle.de> Cc: linux-kernel@vger.kernel.org, Linus Torvalds <torvalds@linux-foundation.org>, linux-mm@kvack.org, Vlastimil Babka <vbabka@suse.cz>, Mel Gorman <mgorman@techsingularity.net>, Joonsoo Kim <iamjoonsoo.kim@lge.com>, David Rientjes <rientjes@google.com>, Rik van Riel <riel@redhat.com>, Michal Hocko <mhocko@suse.com> Subject: [PATCH 2/4] mm, compaction: more reliably increase direct compaction priority Date: Tue, 6 Sep 2016 15:52:56 +0200 [thread overview] Message-ID: <20160906135258.18335-3-vbabka@suse.cz> (raw) In-Reply-To: <20160906135258.18335-1-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> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> --- 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 1df7694f4ec7..f8bed910e3cf 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3174,13 +3174,8 @@ 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 @@ -3204,6 +3199,15 @@ 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 -- 2.9.3 -- 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:[~2016-09-06 13:53 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-09-06 13:52 [PATCH 0/4] reintroduce compaction feedback for OOM decisions Vlastimil Babka 2016-09-06 13:52 ` Vlastimil Babka 2016-09-06 13:52 ` [PATCH 1/4] Revert "mm, oom: prevent premature OOM killer invocation for high order request" Vlastimil Babka 2016-09-06 13:52 ` Vlastimil Babka 2016-09-21 17:04 ` Michal Hocko 2016-09-21 17:04 ` Michal Hocko 2016-09-06 13:52 ` Vlastimil Babka [this message] 2016-09-06 13:52 ` [PATCH 2/4] mm, compaction: more reliably increase direct compaction priority Vlastimil Babka 2016-09-21 17:13 ` Michal Hocko 2016-09-21 17:13 ` Michal Hocko 2016-09-22 12:51 ` Vlastimil Babka 2016-09-22 12:51 ` Vlastimil Babka 2016-09-22 14:08 ` Michal Hocko 2016-09-22 14:08 ` Michal Hocko 2016-09-22 14:52 ` Michal Hocko 2016-09-22 14:52 ` Michal Hocko 2016-09-22 14:59 ` Vlastimil Babka 2016-09-22 14:59 ` Vlastimil Babka 2016-09-22 15:06 ` Vlastimil Babka 2016-09-22 15:06 ` Vlastimil Babka 2016-09-23 4:04 ` Hillf Danton 2016-09-23 4:04 ` Hillf Danton 2016-09-23 6:55 ` Vlastimil Babka 2016-09-23 6:55 ` Vlastimil Babka 2016-09-23 8:23 ` Michal Hocko 2016-09-23 8:23 ` Michal Hocko 2016-09-23 10:47 ` Vlastimil Babka 2016-09-23 10:47 ` Vlastimil Babka 2016-09-23 12:06 ` Michal Hocko 2016-09-23 12:06 ` Michal Hocko 2016-09-06 13:52 ` [PATCH 3/4] mm, compaction: restrict full priority to non-costly orders Vlastimil Babka 2016-09-06 13:52 ` Vlastimil Babka 2016-09-21 17:15 ` Michal Hocko 2016-09-21 17:15 ` Michal Hocko 2016-09-06 13:52 ` [PATCH 4/4] mm, compaction: make full priority ignore pageblock suitability Vlastimil Babka 2016-09-06 13:52 ` Vlastimil Babka 2016-09-15 18:51 ` [PATCH 0/4] reintroduce compaction feedback for OOM decisions Arkadiusz Miskiewicz 2016-09-15 18:51 ` Arkadiusz Miskiewicz 2016-09-21 17:18 ` Michal Hocko 2016-09-21 17:18 ` Michal Hocko 2016-09-22 15:18 ` Vlastimil Babka 2016-09-22 15:18 ` Vlastimil Babka 2016-09-23 8:26 ` Michal Hocko 2016-09-23 8:26 ` Michal Hocko 2016-09-23 10:55 ` Vlastimil Babka 2016-09-23 10:55 ` Vlastimil Babka 2016-09-23 12:09 ` Michal Hocko 2016-09-23 12:09 ` Michal Hocko
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