On Thu 19-02-15 13:29:14, Michal Hocko wrote: [...] > Something like the following. __GFP_HIGH doesn't seem to be sufficient so we would need something slightly else but the idea is still the same: diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8d52ab18fe0d..2d224bbdf8e8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2599,6 +2599,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, enum migrate_mode migration_mode = MIGRATE_ASYNC; bool deferred_compaction = false; int contended_compaction = COMPACT_CONTENDED_NONE; + int oom = 0; /* * In the slowpath, we sanity check order to avoid ever trying to @@ -2635,6 +2636,15 @@ retry: alloc_flags = gfp_to_alloc_flags(gfp_mask); /* + * __GFP_NOFAIL allocations cannot fail but yet the current context + * might be blocking resources needed by the OOM victim to terminate. + * Allow the caller to dive into memory reserves to succeed the + * allocation and break out from a potential deadlock. + */ + if (oom > 10 && (gfp_mask & __GFP_NOFAIL)) + alloc_flags |= ALLOC_NO_WATERMARKS; + + /* * Find the true preferred zone if the allocation is unconstrained by * cpusets. */ @@ -2759,6 +2769,8 @@ retry: goto got_pg; if (!did_some_progress) goto nopage; + + oom++; } /* Wait for some write requests to complete then retry */ wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50); -- Michal Hocko SUSE Labs _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
