On 09/23/2016 06:04 AM, Hillf Danton wrote:
>>
>> ----8<----
>> From a7921e57ba1189b9c08fc4879358a908c390e47c Mon Sep 17 00:00:00 2001
>> From: Vlastimil Babka <vba...@suse.cz>
>> Date: Thu, 22 Sep 2016 17:02:37 +0200
>> Subject: [PATCH] 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.
>>
>> Signed-off-by: Vlastimil Babka <vba...@suse.cz>
>> ---
>>  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 582820080601..a01359ab3ed6 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -3401,16 +3401,26 @@ 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;
> 
> s/no/*no/
>> +    else
>> +            no_progress_loops++;
> 
> s/no_progress_loops/(*no_progress_loops)/

Crap, thanks. I'm asking our gcc guy about possible warnings for this,
and some past mistake I've seen which would be *no_progress_loops++.
 
> With that feel free to add
> Acked-by: Hillf Danton <hillf...@alibaba-inc.com>

Thanks!

----8<----
>From 1623d5bd441160569ffad3808aeeec852048e558 Mon Sep 17 00:00:00 2001
From: Vlastimil Babka <vba...@suse.cz>
Date: Thu, 22 Sep 2016 17:02:37 +0200
Subject: [PATCH] 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...@alibaba-inc.com: fix missing pointer dereferences]
Signed-off-by: Vlastimil Babka <vba...@suse.cz>
Acked-by: Hillf Danton <hillf...@alibaba-inc.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 582820080601..6039ff40452c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3401,16 +3401,26 @@ 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;
 
        /*
@@ -3425,7 +3435,7 @@ 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);
 
@@ -3641,18 +3651,8 @@ __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


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