path: root/mm
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authorVlastimil Babka <vbabka@suse.cz>2017-11-17 15:26:38 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-17 16:10:00 -0800
commit2583d6713267a4c80126e4e50dd45f5cf685ebe8 (patch)
tree36ef91c62bcb906ca280dfface3b4e136d402c45 /mm
parentb527cfe5bc23208cf9a346879501333cec638aba (diff)
mm, compaction: split off flag for not updating skip hints
Pageblock skip hints were added as a heuristic for compaction, which shares core code with CMA. Since CMA reliability would suffer from the heuristics, compact_control flag ignore_skip_hint was added for the CMA use case. Since 6815bf3f233e ("mm/compaction: respect ignore_skip_hint in update_pageblock_skip") the flag also means that CMA won't *update* the skip hints in addition to ignoring them. Today, direct compaction can also ignore the skip hints in the last resort attempt, but there's no reason not to set them when isolation fails in such case. Thus, this patch splits off a new no_set_skip_hint flag to avoid the updating, which only CMA sets. This should improve the heuristics a bit, and allow us to simplify the persistent skip bit handling as the next step. Link: http://lkml.kernel.org/r/20171102121706.21504-2-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
3 files changed, 3 insertions, 1 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index e8f5b4e2cb05..bb1188a9d58e 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -295,7 +295,7 @@ static void update_pageblock_skip(struct compact_control *cc,
struct zone *zone = cc->zone;
unsigned long pfn;
- if (cc->ignore_skip_hint)
+ if (cc->no_set_skip_hint)
if (!page)
diff --git a/mm/internal.h b/mm/internal.h
index 1df011f62480..e6bd35182dae 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -198,6 +198,7 @@ struct compact_control {
const int classzone_idx; /* zone index of a direct compactor */
enum migrate_mode mode; /* Async or sync migration mode */
bool ignore_skip_hint; /* Scan blocks even if marked skip */
+ bool no_set_skip_hint; /* Don't mark blocks for skipping */
bool ignore_block_suitable; /* Scan blocks considered unsuitable */
bool direct_compaction; /* False from kcompactd or /proc/... */
bool whole_zone; /* Whole zone should/has been scanned */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 55ded92f9809..d4096f4a5c1f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7619,6 +7619,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
.zone = page_zone(pfn_to_page(start)),
.ignore_skip_hint = true,
+ .no_set_skip_hint = true,
.gfp_mask = current_gfp_context(gfp_mask),