1 files changed, 32 insertions, 72 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index cae21dc9d54e..2880f6f61d05 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2309,48 +2309,6 @@ void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
 		show_mem(filter);
 }
 
-static inline int
-should_alloc_retry(gfp_t gfp_mask, unsigned int order,
-				unsigned long did_some_progress,
-				unsigned long pages_reclaimed)
-{
-	/* Do not loop if specifically requested */
-	if (gfp_mask & __GFP_NORETRY)
-		return 0;
-
-	/* Always retry if specifically requested */
-	if (gfp_mask & __GFP_NOFAIL)
-		return 1;
-
-	/*
-	 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
-	 * making forward progress without invoking OOM. Suspend also disables
-	 * storage devices so kswapd will not help. Bail if we are suspending.
-	 */
-	if (!did_some_progress && pm_suspended_storage())
-		return 0;
-
-	/*
-	 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
-	 * means __GFP_NOFAIL, but that may not be true in other
-	 * implementations.
-	 */
-	if (order <= PAGE_ALLOC_COSTLY_ORDER)
-		return 1;
-
-	/*
-	 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
-	 * specified, then we retry until we no longer reclaim any pages
-	 * (above), or we've reclaimed an order of pages at least as
-	 * large as the allocation's order. In both cases, if the
-	 * allocation still fails, we stop retrying.
-	 */
-	if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
-		return 1;
-
-	return 0;
-}
-
 static inline struct page *
 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
 	const struct alloc_context *ac, unsigned long *did_some_progress)
@@ -2389,16 +2347,18 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
 		/* The OOM killer does not needlessly kill tasks for lowmem */
 		if (ac->high_zoneidx < ZONE_NORMAL)
 			goto out;
-		/* The OOM killer does not compensate for light reclaim */
+		/* The OOM killer does not compensate for IO-less reclaim */
 		if (!(gfp_mask & __GFP_FS)) {
 			/*
 			 * XXX: Page reclaim didn't yield anything,
 			 * and the OOM killer can't be invoked, but
-			 * keep looping as per should_alloc_retry().
+			 * keep looping as per tradition.
 			 */
 			*did_some_progress = 1;
 			goto out;
 		}
+		if (pm_suspended_storage())
+			goto out;
 		/* The OOM killer may not free memory on a specific node */
 		if (gfp_mask & __GFP_THISNODE)
 			goto out;
@@ -2781,40 +2741,40 @@ retry:
 	if (page)
 		goto got_pg;
 
-	/* Check if we should retry the allocation */
+	/* Do not loop if specifically requested */
+	if (gfp_mask & __GFP_NORETRY)
+		goto noretry;
+
+	/* Keep reclaiming pages as long as there is reasonable progress */
 	pages_reclaimed += did_some_progress;
-	if (should_alloc_retry(gfp_mask, order, did_some_progress,
-						pages_reclaimed)) {
-		/*
-		 * If we fail to make progress by freeing individual
-		 * pages, but the allocation wants us to keep going,
-		 * start OOM killing tasks.
-		 */
-		if (!did_some_progress) {
-			page = __alloc_pages_may_oom(gfp_mask, order, ac,
-							&did_some_progress);
-			if (page)
-				goto got_pg;
-			if (!did_some_progress)
-				goto nopage;
-		}
+	if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||
+	    ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) {
 		/* Wait for some write requests to complete then retry */
 		wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50);
 		goto retry;
-	} else {
-		/*
-		 * High-order allocations do not necessarily loop after
-		 * direct reclaim and reclaim/compaction depends on compaction
-		 * being called after reclaim so call directly if necessary
-		 */
-		page = __alloc_pages_direct_compact(gfp_mask, order,
-					alloc_flags, ac, migration_mode,
-					&contended_compaction,
-					&deferred_compaction);
-		if (page)
-			goto got_pg;
 	}
 
+	/* Reclaim has failed us, start killing things */
+	page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
+	if (page)
+		goto got_pg;
+
+	/* Retry as long as the OOM killer is making progress */
+	if (did_some_progress)
+		goto retry;
+
+noretry:
+	/*
+	 * High-order allocations do not necessarily loop after
+	 * direct reclaim and reclaim/compaction depends on compaction
+	 * being called after reclaim so call directly if necessary
+	 */
+	page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags,
+					    ac, migration_mode,
+					    &contended_compaction,
+					    &deferred_compaction);
+	if (page)
+		goto got_pg;
 nopage:
 	warn_alloc_failed(gfp_mask, order, NULL);
 got_pg: