Messages in this thread | | | Subject | Re: [PATCH v6 06/11] mm, compaction: more reliably increase direct compaction priority | From | Vlastimil Babka <> | Date | Tue, 16 Aug 2016 08:31:13 +0200 |
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On 08/16/2016 08:07 AM, Joonsoo Kim wrote: >> 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; > > The only difference that this patch makes is increasing priority when > COMPACT_PARTIAL(COMPACTION_SUCCESS) returns. In that case, we can
Hm it's true that I adjusted this patch from the previous version, before realizing that PARTIAL is now SUCCESS.
> usually allocate high-order freepage so we would not enter here. Am I > missing something? Is it really needed behaviour change?
It will likely be rare when this triggers, when compaction success doesn't lead to allocation success due to parallel allocation activity.
> Thanks. >
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