Messages in this thread Patch in this message | | | Date | Fri, 28 Sep 2012 09:37:22 +0100 | From | Mel Gorman <> | Subject | Re: CMA broken in next-20120926 |
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> I hope this patch fixes the bug. If this patch fixes the problem > but has some problem about description or someone has better idea, > feel free to modify and resend to akpm, Please. >
A full revert is overkill. Can the following patch be tested as a potential replacement please?
---8<--- mm: compaction: Iron out isolate_freepages_block() and isolate_freepages_range() -fix1
CMA is reported to be broken in next-20120926. Minchan Kim pointed out that this was due to nr_scanned != total_isolated in the case of CMA because PageBuddy pages are one scan but many isolations in CMA. This patch should address the problem.
This patch is a fix for mm-compaction-acquire-the-zone-lock-as-late-as-possible-fix-2.patch
Signed-off-by: Mel Gorman <mgorman@suse.de> --- mm/compaction.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/mm/compaction.c b/mm/compaction.c index 8250b69..d6e260a 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -282,6 +282,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, { int nr_scanned = 0, total_isolated = 0; struct page *cursor, *valid_page = NULL; + unsigned long nr_strict_required = end_pfn - blockpfn; unsigned long flags; bool locked = false; @@ -343,10 +344,10 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, /* * If strict isolation is requested by CMA then check that all the - * pages scanned were isolated. If there were any failures, 0 is + * pages requested were isolated. If there were any failures, 0 is * returned and CMA will fail. */ - if (strict && nr_scanned != total_isolated) + if (strict && nr_strict_required != total_isolated) total_isolated = 0; if (locked)
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