linux-kernel - [PATCH 2/4] mm, page_alloc: pull no_progress_loops update to should_reclaim

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Message-Id: <20160926162025.21555-3-vbabka@suse.cz>
Date:   Mon, 26 Sep 2016 18:20:23 +0200
From:   Vlastimil Babka <vbabka@...e.cz>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Arkadiusz Miskiewicz <a.miskiewicz@...il.com>,
        Ralf-Peter Rohbeck <Ralf-Peter.Rohbeck@...ntum.com>,
        Olaf Hering <olaf@...fle.de>, Vlastimil Babka <vbabka@...e.cz>,
        Mel Gorman <mgorman@...hsingularity.net>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        David Rientjes <rientjes@...gle.com>,
        Rik van Riel <riel@...hat.com>,
        Hillf Danton <hillf.zj@...baba-inc.com>,
        Michal Hocko <mhocko@...nel.org>,
        Michal Hocko <mhocko@...e.com>
Subject: [PATCH 2/4] mm, page_alloc: pull no_progress_loops update to should_reclaim_retry()

The should_reclaim_retry() makes decisions based on no_progress_loops, so it
makes sense to also update the counter there. It will be also consistent with
should_compact_retry() and compaction_retries. No functional change.

[hillf.zj@...baba-inc.com: fix missing pointer dereferences]
Signed-off-by: Vlastimil Babka <vbabka@...e.cz>
Acked-by: Hillf Danton <hillf.zj@...baba-inc.com>
Acked-by: Michal Hocko <mhocko@...e.com>
Cc: Mel Gorman <mgorman@...hsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@....com>
Cc: David Rientjes <rientjes@...gle.com>
Cc: Rik van Riel <riel@...hat.com>
---
 mm/page_alloc.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0fd29731ab35..8ed4f506ae0b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3404,16 +3404,26 @@ bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
 static inline bool
 should_reclaim_retry(gfp_t gfp_mask, unsigned order,
 		     struct alloc_context *ac, int alloc_flags,
-		     bool did_some_progress, int no_progress_loops)
+		     bool did_some_progress, int *no_progress_loops)
 {
 	struct zone *zone;
 	struct zoneref *z;
 
 	/*
+	 * Costly allocations might have made a progress but this doesn't mean
+	 * their order will become available due to high fragmentation so
+	 * always increment the no progress counter for them
+	 */
+	if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
+		*no_progress_loops = 0;
+	else
+		(*no_progress_loops)++;
+
+	/*
 	 * Make sure we converge to OOM if we cannot make any progress
 	 * several times in the row.
 	 */
-	if (no_progress_loops > MAX_RECLAIM_RETRIES)
+	if (*no_progress_loops > MAX_RECLAIM_RETRIES)
 		return false;
 
 	/*
@@ -3428,7 +3438,7 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order,
 		unsigned long reclaimable;
 
 		available = reclaimable = zone_reclaimable_pages(zone);
-		available -= DIV_ROUND_UP(no_progress_loops * available,
+		available -= DIV_ROUND_UP((*no_progress_loops) * available,
 					  MAX_RECLAIM_RETRIES);
 		available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
 
@@ -3650,18 +3660,8 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
 	if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT))
 		goto nopage;
 
-	/*
-	 * Costly allocations might have made a progress but this doesn't mean
-	 * their order will become available due to high fragmentation so
-	 * always increment the no progress counter for them
-	 */
-	if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER)
-		no_progress_loops = 0;
-	else
-		no_progress_loops++;
-
 	if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
-				 did_some_progress > 0, no_progress_loops))
+				 did_some_progress > 0, &no_progress_loops))
 		goto retry;
 
 	/*
-- 
2.10.0