From: Muchun Song <songmuchun@bytedance.com>
To: akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH] mm/page_alloc: speeding up the iteration of max_order
Date: Wed, 2 Dec 2020 20:18:38 +0800 [thread overview]
Message-ID: <20201202121838.75218-1-songmuchun@bytedance.com> (raw)
When we free a page whose order is very close to MAX_ORDER and greater
than pageblock_order, it wastes some CPU cycles to increase max_order
to MAX_ORDER one by one and check the pageblock migratetype of that page
repeatedly especially when MAX_ORDER is much larger than pageblock_order.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
mm/page_alloc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 141f12e5142c..959541234e1d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1041,7 +1041,7 @@ static inline void __free_one_page(struct page *page,
pfn = combined_pfn;
order++;
}
- if (max_order < MAX_ORDER) {
+ if (max_order < MAX_ORDER && order < MAX_ORDER - 1) {
/* If we are here, it means order is >= pageblock_order.
* We want to prevent merge between freepages on isolate
* pageblock and normal pageblock. Without this, pageblock
@@ -1062,6 +1062,8 @@ static inline void __free_one_page(struct page *page,
is_migrate_isolate(buddy_mt)))
goto done_merging;
}
+ if (unlikely(order != max_order - 1))
+ max_order = order + 1;
max_order++;
goto continue_merging;
}
--
2.11.0
next reply other threads:[~2020-12-02 12:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 12:18 Muchun Song [this message]
2020-12-03 17:37 ` [PATCH] mm/page_alloc: speeding up the iteration of max_order Vlastimil Babka
2020-12-04 4:03 ` [External] " Muchun Song
2020-12-04 10:28 ` Vlastimil Babka
2020-12-04 11:11 ` Muchun Song
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