From 7e95430e4232f55bfd8f1728fb620957912c32f4 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Thu, 28 Aug 2014 19:35:03 +0100 Subject: mm, compaction: add per-zone migration pfn cache for async compaction commit 35979ef3393110ff3c12c6b94552208d3bdf1a36 upstream. Each zone has a cached migration scanner pfn for memory compaction so that subsequent calls to memory compaction can start where the previous call left off. Currently, the compaction migration scanner only updates the per-zone cached pfn when pageblocks were not skipped for async compaction. This creates a dependency on calling sync compaction to avoid having subsequent calls to async compaction from scanning an enormous amount of non-MOVABLE pageblocks each time it is called. On large machines, this could be potentially very expensive. This patch adds a per-zone cached migration scanner pfn only for async compaction. It is updated everytime a pageblock has been scanned in its entirety and when no pages from it were successfully isolated. The cached migration scanner pfn for sync compaction is updated only when called for sync compaction. Signed-off-by: David Rientjes Acked-by: Vlastimil Babka Reviewed-by: Naoya Horiguchi Cc: Greg Thelen Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Mel Gorman Signed-off-by: Jiri Slaby --- include/linux/mmzone.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 4719985279c1..e4d1a889e094 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -361,9 +361,10 @@ struct zone { /* Set to true when the PG_migrate_skip bits should be cleared */ bool compact_blockskip_flush; - /* pfns where compaction scanners should start */ + /* pfn where compaction free scanner should start */ unsigned long compact_cached_free_pfn; - unsigned long compact_cached_migrate_pfn; + /* pfn where async and sync compaction migration scanner should start */ + unsigned long compact_cached_migrate_pfn[2]; #endif #ifdef CONFIG_MEMORY_HOTPLUG /* see spanned/present_pages for more description */ -- cgit v1.2.3