diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 40 |
1 files changed, 25 insertions, 15 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 1731236dec35..3b21a13d841c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -773,9 +773,12 @@ again: } #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */ -#define ALLOC_HARDER 0x02 /* try to alloc harder */ -#define ALLOC_HIGH 0x04 /* __GFP_HIGH set */ -#define ALLOC_CPUSET 0x08 /* check for correct cpuset */ +#define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */ +#define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */ +#define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ +#define ALLOC_HARDER 0x10 /* try to alloc harder */ +#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ +#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ /* * Return 1 if free pages are above 'mark'. This takes into account the order @@ -830,7 +833,14 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, continue; if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { - if (!zone_watermark_ok(*z, order, (*z)->pages_low, + unsigned long mark; + if (alloc_flags & ALLOC_WMARK_MIN) + mark = (*z)->pages_min; + else if (alloc_flags & ALLOC_WMARK_LOW) + mark = (*z)->pages_low; + else + mark = (*z)->pages_high; + if (!zone_watermark_ok(*z, order, mark, classzone_idx, alloc_flags)) continue; } @@ -871,7 +881,7 @@ restart: } page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, - zonelist, ALLOC_CPUSET); + zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET); if (page) goto got_pg; @@ -888,7 +898,7 @@ restart: * cannot run direct reclaim, or if the caller has realtime scheduling * policy. */ - alloc_flags = 0; + alloc_flags = ALLOC_WMARK_MIN; if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait) alloc_flags |= ALLOC_HARDER; if (gfp_mask & __GFP_HIGH) @@ -959,7 +969,7 @@ rebalance: * under heavy pressure. */ page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, - zonelist, ALLOC_CPUSET); + zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET); if (page) goto got_pg; @@ -1762,16 +1772,16 @@ static int __devinit zone_batchsize(struct zone *zone) batch = 1; /* - * We will be trying to allcoate bigger chunks of contiguous - * memory of the order of fls(batch). This should result in - * better cache coloring. + * Clamp the batch to a 2^n - 1 value. Having a power + * of 2 value was found to be more likely to have + * suboptimal cache aliasing properties in some cases. * - * A sanity check also to ensure that batch is still in limits. + * For example if 2 tasks are alternately allocating + * batches of pages, one task can end up with a lot + * of pages of one half of the possible page colors + * and the other with pages of the other colors. */ - batch = (1 << fls(batch + batch/2)); - - if (fls(batch) >= (PAGE_SHIFT + MAX_ORDER - 2)) - batch = PAGE_SHIFT + ((MAX_ORDER - 1 - PAGE_SHIFT)/2); + batch = (1 << (fls(batch + batch/2)-1)) - 1; return batch; } |