Commit 6b4e3181d7bd ("mm, oom: prevent premature OOM killer invocation for high
order request") was intended as a quick fix of OOM regressions for 4.8 and
stable 4.7.x kernels. For a better long-term solution, we still want to
consider compaction feedback, which should be possible after some more
improvements in the following patches.This reverts commit 6b4e3181d7bd5ca5ab6f45929e4a5ffa7ab4ab7f. Signed-off-by: Vlastimil Babka <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: David Rientjes <[email protected]> Cc: Rik van Riel <[email protected]> --- mm/page_alloc.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 49 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ee3997859f14..1df7694f4ec7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3158,6 +3158,54 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, return NULL; } +static inline bool +should_compact_retry(struct alloc_context *ac, int order, int alloc_flags, + enum compact_result compact_result, + enum compact_priority *compact_priority, + int compaction_retries) +{ + int max_retries = MAX_COMPACT_RETRIES; + + if (!order) + return false; + + /* + * compaction considers all the zone as desperately out of memory + * 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; + } + + /* + * make sure the compaction wasn't deferred or didn't bail out early + * due to locks contention before we declare that we should give up. + * But do not retry if the given zonelist is not suitable for + * compaction. + */ + if (compaction_withdrawn(compact_result)) + return compaction_zonelist_suitable(ac, order, alloc_flags); + + /* + * !costly requests are much more important than __GFP_REPEAT + * costly ones because they are de facto nofail and invoke OOM + * killer to move on while costly can fail and users are ready + * to cope with that. 1/4 retries is rather arbitrary but we + * would need much more detailed feedback from compaction to + * make a better decision. + */ + if (order > PAGE_ALLOC_COSTLY_ORDER) + max_retries /= 4; + if (compaction_retries <= max_retries) + return true; + + return false; +} #else static inline struct page * __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, @@ -3168,8 +3216,6 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, return NULL; } -#endif /* CONFIG_COMPACTION */ - static inline bool should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags, enum compact_result compact_result, @@ -3196,6 +3242,7 @@ should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_fla } return false; } +#endif /* CONFIG_COMPACTION */ /* Perform direct synchronous page reclaim */ static int -- 2.9.3
