Commit dc13292c authored by Kemeng Shi's avatar Kemeng Shi Committed by Andrew Morton
Browse files

mm/compaction: remove unnecessary cursor page in isolate_freepages_block 

The cursor is only used for page forward currently.  We can simply move
page forward directly to remove unnecessary cursor.

Link: https://lkml.kernel.org/r/20230803094901.2915942-4-shikemeng@huaweicloud.com


Signed-off-by: default avatarKemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: default avatarBaolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kemeng Shi <shikemeng@huawei.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent a2864a67

mm/compaction.c

+5 −6
Original line number Diff line number Diff line
@@ -589,7 +589,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, 
				bool strict)

{

	int nr_scanned = 0, total_isolated = 0;

	struct page *cursor;

	struct page *page;

	unsigned long flags = 0;

	bool locked = false;

	unsigned long blockpfn = *start_pfn;
@@ -599,12 +599,11 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, 
	if (strict)

		stride = 1;



	cursor = pfn_to_page(blockpfn);

	page = pfn_to_page(blockpfn);



	/* Isolate free pages. */

	for (; blockpfn < end_pfn; blockpfn += stride, cursor += stride) {

	for (; blockpfn < end_pfn; blockpfn += stride, page += stride) {

		int isolated;

		struct page *page = cursor;



		/*

		 * Periodically drop the lock (if held) regardless of its
@@ -629,7 +628,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, 


			if (likely(order <= MAX_ORDER)) {

				blockpfn += (1UL << order) - 1;

				cursor += (1UL << order) - 1;

				page += (1UL << order) - 1;

				nr_scanned += (1UL << order) - 1;

			}

			goto isolate_fail;
@@ -666,7 +665,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, 
		}

		/* Advance to the end of split page */

		blockpfn += isolated - 1;

		cursor += isolated - 1;

		page += isolated - 1;

		continue;



isolate_fail: