diff options
| -rw-r--r-- | mm/page_alloc.c | 66 |
1 files changed, 36 insertions, 30 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ce2409ee2144..1b2f7b3bba34 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3486,6 +3486,29 @@ static noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) } ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE); +static inline long __zone_watermark_unusable_free(struct zone *z, + unsigned int order, unsigned int alloc_flags) +{ + const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM)); + long unusable_free = (1 << order) - 1; + + /* + * If the caller does not have rights to ALLOC_HARDER then subtract + * the high-atomic reserves. This will over-estimate the size of the + * atomic reserve but it avoids a search. + */ + if (likely(!alloc_harder)) + unusable_free += z->nr_reserved_highatomic; + +#ifdef CONFIG_CMA + /* If allocation can't use CMA areas don't use free CMA pages */ + if (!(alloc_flags & ALLOC_CMA)) + unusable_free += zone_page_state(z, NR_FREE_CMA_PAGES); +#endif + + return unusable_free; +} + /* * Return true if free base pages are above 'mark'. For high-order checks it * will return true of the order-0 watermark is reached and there is at least @@ -3501,19 +3524,12 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM)); /* free_pages may go negative - that's OK */ - free_pages -= (1 << order) - 1; + free_pages -= __zone_watermark_unusable_free(z, order, alloc_flags); if (alloc_flags & ALLOC_HIGH) min -= min / 2; - /* - * If the caller does not have rights to ALLOC_HARDER then subtract - * the high-atomic reserves. This will over-estimate the size of the - * atomic reserve but it avoids a search. - */ - if (likely(!alloc_harder)) { - free_pages -= z->nr_reserved_highatomic; - } else { + if (unlikely(alloc_harder)) { /* * OOM victims can try even harder than normal ALLOC_HARDER * users on the grounds that it's definitely going to be in @@ -3526,13 +3542,6 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, min -= min / 4; } - -#ifdef CONFIG_CMA - /* If allocation can't use CMA areas don't use free CMA pages */ - if (!(alloc_flags & ALLOC_CMA)) - free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES); -#endif - /* * Check watermarks for an order-0 allocation request. If these * are not met, then a high-order request also cannot go ahead @@ -3581,25 +3590,22 @@ static inline bool zone_watermark_fast(struct zone *z, unsigned int order, unsigned long mark, int highest_zoneidx, unsigned int alloc_flags) { - long free_pages = zone_page_state(z, NR_FREE_PAGES); - long cma_pages = 0; + long free_pages; -#ifdef CONFIG_CMA - /* If allocation can't use CMA areas don't use free CMA pages */ - if (!(alloc_flags & ALLOC_CMA)) - cma_pages = zone_page_state(z, NR_FREE_CMA_PAGES); -#endif + free_pages = zone_page_state(z, NR_FREE_PAGES); /* * Fast check for order-0 only. If this fails then the reserves - * need to be calculated. There is a corner case where the check - * passes but only the high-order atomic reserve are free. If - * the caller is !atomic then it'll uselessly search the free - * list. That corner case is then slower but it is harmless. + * need to be calculated. */ - if (!order && (free_pages - cma_pages) > - mark + z->lowmem_reserve[highest_zoneidx]) - return true; + if (!order) { + long fast_free; + + fast_free = free_pages; + fast_free -= __zone_watermark_unusable_free(z, 0, alloc_flags); + if (fast_free > mark + z->lowmem_reserve[highest_zoneidx]) + return true; + } return __zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags, free_pages); |