diff options
-rw-r--r-- | mm/page_alloc.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index b257720edfc8..3b21a13d841c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c | |||
@@ -1772,16 +1772,16 @@ static int __devinit zone_batchsize(struct zone *zone) | |||
1772 | batch = 1; | 1772 | batch = 1; |
1773 | 1773 | ||
1774 | /* | 1774 | /* |
1775 | * We will be trying to allcoate bigger chunks of contiguous | 1775 | * Clamp the batch to a 2^n - 1 value. Having a power |
1776 | * memory of the order of fls(batch). This should result in | 1776 | * of 2 value was found to be more likely to have |
1777 | * better cache coloring. | 1777 | * suboptimal cache aliasing properties in some cases. |
1778 | * | 1778 | * |
1779 | * A sanity check also to ensure that batch is still in limits. | 1779 | * For example if 2 tasks are alternately allocating |
1780 | * batches of pages, one task can end up with a lot | ||
1781 | * of pages of one half of the possible page colors | ||
1782 | * and the other with pages of the other colors. | ||
1780 | */ | 1783 | */ |
1781 | batch = (1 << fls(batch + batch/2)); | 1784 | batch = (1 << (fls(batch + batch/2)-1)) - 1; |
1782 | |||
1783 | if (fls(batch) >= (PAGE_SHIFT + MAX_ORDER - 2)) | ||
1784 | batch = PAGE_SHIFT + ((MAX_ORDER - 1 - PAGE_SHIFT)/2); | ||
1785 | 1785 | ||
1786 | return batch; | 1786 | return batch; |
1787 | } | 1787 | } |