Re: [PATCH v4 1/7] mm: page_alloc: avoid merging non-fallbackable pageblocks with others.
From: Mel Gorman <hidden>
Date: 2022-01-24 16:43:35
Also in:
linux-iommu, linux-mm, lkml, virtualization
On Mon, Jan 24, 2022 at 11:12:07AM -0500, Zi Yan wrote:
On 24 Jan 2022, at 9:02, Mel Gorman wrote:quoted
On Wed, Jan 19, 2022 at 02:06:17PM -0500, Zi Yan wrote:quoted
From: Zi Yan <ziy@nvidia.com> This is done in addition to MIGRATE_ISOLATE pageblock merge avoidance. It prepares for the upcoming removal of the MAX_ORDER-1 alignment requirement for CMA and alloc_contig_range(). MIGRARTE_HIGHATOMIC should not merge with other migratetypes like MIGRATE_ISOLATE and MIGRARTE_CMA[1], so this commit prevents that too. Also add MIGRARTE_HIGHATOMIC to fallbacks array for completeness. [1] https://lore.kernel.org/linux-mm/20211130100853.GP3366@techsingularity.net/ (local) Signed-off-by: Zi Yan <ziy@nvidia.com> <SNIP>@@ -2484,6 +2483,7 @@ static int fallbacks[MIGRATE_TYPES][3] = { [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES }, [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES }, [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES }, + [MIGRATE_HIGHATOMIC] = { MIGRATE_TYPES }, /* Never used */ #ifdef CONFIG_CMA [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */ #endifIf it's never used, why is it added?Just to make the fallbacks list complete, since MIGRATE_CMA and MIGRATE_ISOLATE are in the list. Instead, I can remove MIGRATE_CMA and MIGRATE_ISOLATE. WDYT?
It probably makes more sense to remove them or replace them with a comment stating what migratetypes do not have a fallback list. Do it as a separate patch that stands alone. It does not need to be part of this series. -- Mel Gorman SUSE Labs