[PATCH v3 1/3] mm/free_pcppages_bulk: update pcp->count inside

[Aaron Lu]

Matthew Wilcox found that all callers of free_pcppages_bulk() currently
update pcp->count immediately after so it's natural to do it inside
free_pcppages_bulk().

No functionality or performance change is expected from this patch.

Suggested-by: Matthew Wilcox <wi...@infradead.org>
Signed-off-by: Aaron Lu <aaron...@intel.com>
---
 mm/page_alloc.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index cb416723538f..3154859cccd6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1117,6 +1117,7 @@ static void free_pcppages_bulk(struct zone *zone, int 
count,
        int batch_free = 0;
        bool isolated_pageblocks;
 
+       pcp->count -= count;
        spin_lock(&zone->lock);
        isolated_pageblocks = has_isolate_pageblock(zone);
 
@@ -2416,10 +2417,8 @@ void drain_zone_pages(struct zone *zone, struct 
per_cpu_pages *pcp)
        local_irq_save(flags);
        batch = READ_ONCE(pcp->batch);
        to_drain = min(pcp->count, batch);
-       if (to_drain > 0) {
+       if (to_drain > 0)
                free_pcppages_bulk(zone, to_drain, pcp);
-               pcp->count -= to_drain;
-       }
        local_irq_restore(flags);
 }
 #endif
@@ -2441,10 +2440,8 @@ static void drain_pages_zone(unsigned int cpu, struct 
zone *zone)
        pset = per_cpu_ptr(zone->pageset, cpu);
 
        pcp = &pset->pcp;
-       if (pcp->count) {
+       if (pcp->count)
                free_pcppages_bulk(zone, pcp->count, pcp);
-               pcp->count = 0;
-       }
        local_irq_restore(flags);
 }
 
@@ -2668,7 +2665,6 @@ static void free_unref_page_commit(struct page *page, 
unsigned long pfn)
        if (pcp->count >= pcp->high) {
                unsigned long batch = READ_ONCE(pcp->batch);
                free_pcppages_bulk(zone, batch, pcp);
-               pcp->count -= batch;
        }
 }
 
-- 
2.14.3