Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1171787

[RFC PATCH 01/10] mm/compaction: update skip-bit if whole pageblock is really scanned

Show all headers | View raw

Scanning pageblock is stopped at the middle of pageblock if enough
pages are isolated. In the next run, it begins again at this position
and if it find that there is no isolation candidate from the middle of
pageblock to end of pageblock, it updates skip-bit. In this case,
scanner doesn't start at begin of pageblock so it is not appropriate
to set skipbit. This patch fixes this situation that updating skip-bit
only happens when whole pageblock is really scanned.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
---
 mm/compaction.c | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index 6ef2fdf..4397bf7 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -261,7 +261,8 @@ void reset_isolation_suitable(pg_data_t *pgdat)
  */
 static void update_pageblock_skip(struct compact_control *cc,
 			struct page *page, unsigned long nr_isolated,
-			bool migrate_scanner)
+			unsigned long start_pfn, unsigned long end_pfn,
+			unsigned long curr_pfn, bool migrate_scanner)
 {
 	struct zone *zone = cc->zone;
 	unsigned long pfn;
@@ -275,6 +276,13 @@ static void update_pageblock_skip(struct compact_control *cc,
 	if (nr_isolated)
 		return;
 
+	/* Update the pageblock-skip if the whole pageblock was scanned */
+	if (curr_pfn != end_pfn)
+		return;
+
+	if (start_pfn != round_down(end_pfn - 1, pageblock_nr_pages))
+		return;
+
 	set_pageblock_skip(page);
 
 	pfn = page_to_pfn(page);
@@ -300,7 +308,8 @@ static inline bool isolation_suitable(struct compact_control *cc,
 
 static void update_pageblock_skip(struct compact_control *cc,
 			struct page *page, unsigned long nr_isolated,
-			bool migrate_scanner)
+			unsigned long start_pfn, unsigned long end_pfn,
+			unsigned long curr_pfn, bool migrate_scanner)
 {
 }
 #endif /* CONFIG_COMPACTION */
@@ -493,9 +502,6 @@ isolate_fail:
 	trace_mm_compaction_isolate_freepages(*start_pfn, blockpfn,
 					nr_scanned, total_isolated);
 
-	/* Record how far we have got within the block */
-	*start_pfn = blockpfn;
-
 	/*
 	 * If strict isolation is requested by CMA then check that all the
 	 * pages requested were isolated. If there were any failures, 0 is
@@ -507,9 +513,11 @@ isolate_fail:
 	if (locked)
 		spin_unlock_irqrestore(&cc->zone->lock, flags);
 
-	/* Update the pageblock-skip if the whole pageblock was scanned */
-	if (blockpfn == end_pfn)
-		update_pageblock_skip(cc, valid_page, total_isolated, false);
+	update_pageblock_skip(cc, valid_page, total_isolated,
+			*start_pfn, end_pfn, blockpfn, false);
+
+	/* Record how far we have got within the block */
+	*start_pfn = blockpfn;
 
 	count_compact_events(COMPACTFREE_SCANNED, nr_scanned);
 	if (total_isolated)
@@ -806,12 +814,8 @@ isolate_success:
 	if (locked)
 		spin_unlock_irqrestore(&zone->lru_lock, flags);
 
-	/*
-	 * Update the pageblock-skip information and cached scanner pfn,
-	 * if the whole pageblock was scanned without isolating any page.
-	 */
-	if (low_pfn == end_pfn)
-		update_pageblock_skip(cc, valid_page, nr_isolated, true);
+	update_pageblock_skip(cc, valid_page, nr_isolated,
+			start_pfn, end_pfn, low_pfn, true);
 
 	trace_mm_compaction_isolate_migratepages(start_pfn, low_pfn,
 						nr_scanned, nr_isolated);
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[RFC PATCH 00/10] redesign compaction algorithm Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2015-06-25 02:50 +0200
  [RFC PATCH 04/10] mm/compaction: clean-up restarting condition check Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2015-06-25 02:50 +0200
  [RFC PATCH 08/10] mm/compaction: remove compaction deferring Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2015-06-25 02:50 +0200
  [RFC PATCH 03/10] mm/compaction: always update cached pfn Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2015-06-25 02:50 +0200
    Re: [RFC PATCH 03/10] mm/compaction: always update cached pfn Vlastimil Babka <vbabka@suse.cz> - 2015-06-25 11:10 +0200
  [RFC PATCH 05/10] mm/compaction: make freepage scanner scans non-movable pageblock Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2015-06-25 02:50 +0200
  [RFC PATCH 01/10] mm/compaction: update skip-bit if whole pageblock is really scanned Joonsoo Kim <iamjoonsoo.kim@lge.com> - 2015-06-25 02:50 +0200
  Re: [RFC PATCH 00/10] redesign compaction algorithm Joonsoo Kim <js1304@gmail.com> - 2015-06-26 04:10 +0200
  Re: [RFC PATCH 00/10] redesign compaction algorithm Joonsoo Kim <js1304@gmail.com> - 2015-06-26 04:20 +0200

csiph-web