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 <vbabka@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
---
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
--
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