linux-kernel - [PATCH 1/2] mm/page_alloc: remove track of active PCP lists range in bulk free

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Message-Id: <20230809100754.3094517-2-shikemeng@huaweicloud.com>
Date:   Wed,  9 Aug 2023 18:07:53 +0800
From:   Kemeng Shi <shikemeng@...weicloud.com>
To:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        akpm@...ux-foundation.org, baolin.wang@...ux.alibaba.com,
        mgorman@...hsingularity.net, david@...hat.com, willy@...radead.org
Cc:     shikemeng@...weicloud.com
Subject: [PATCH 1/2] mm/page_alloc: remove track of active PCP lists range in bulk free

After commit fd56eef258a17 ("mm/page_alloc: simplify how many pages are
selected per pcp list during bulk free"), we will drain all pages in
selected pcp list. And we ensured passed count is < pcp->count. Then,
the search will finish before wrap-around and track of active PCP lists
range intended for wrap-around case is no longer needed.

Signed-off-by: Kemeng Shi <shikemeng@...weicloud.com>
---
 mm/page_alloc.c | 15 +++------------
 1 file changed, 3 insertions(+), 12 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 96b7c1a7d1f2..1ddcb2707d05 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1207,8 +1207,6 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 					int pindex)
 {
 	unsigned long flags;
-	int min_pindex = 0;
-	int max_pindex = NR_PCP_LISTS - 1;
 	unsigned int order;
 	bool isolated_pageblocks;
 	struct page *page;
@@ -1231,17 +1229,10 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 
 		/* Remove pages from lists in a round-robin fashion. */
 		do {
-			if (++pindex > max_pindex)
-				pindex = min_pindex;
+			if (++pindex > NR_PCP_LISTS - 1)
+				pindex = 0;
 			list = &pcp->lists[pindex];
-			if (!list_empty(list))
-				break;
-
-			if (pindex == max_pindex)
-				max_pindex--;
-			if (pindex == min_pindex)
-				min_pindex++;
-		} while (1);
+		} while (list_empty(list));
 
 		order = pindex_to_order(pindex);
 		nr_pages = 1 << order;
-- 
2.30.0