Commit f142b2c2 authored Aug 09, 2023 by Kemeng Shi Committed by Andrew Morton Aug 21, 2023

mm/page_alloc: remove track of active PCP lists range in bulk free

Patch series "Two minor cleanups for pcp list in page_alloc".

There are two minor cleanups for pcp list in page_alloc. More details
can be found in respective patches.


This patch (of 2):

After commit fd56eef2 ("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.

Link: https://lkml.kernel.org/r/20230809100754.3094517-1-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20230809100754.3094517-2-shikemeng@huaweicloud.com


Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

parent 1a8c64e1

mm/page_alloc.c

+3 −12

Original line number	Diff line number	Diff line
		@@ -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;