Hi,
On 09/28/2012 11:37 AM, Mel Gorman wrote:
>> 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@xxxxxxx>
linux-next + this patch alone also works for me.
Tested-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> ---
> 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)
>
--
Péter
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>