diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 656295865d58419ad52b3d46e84908dd33769669..91812df1351af652f6e2f7c3a7612a5df473140d 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -368,9 +368,25 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp); void drain_all_pages(void); void drain_local_pages(void *dummy); +/* + * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what + * GFP flags are used before interrupts are enabled. Once interrupts are + * enabled, it is set to __GFP_BITS_MASK while the system is running. During + * hibernation, it is used by PM to avoid I/O during memory allocation while + * devices are suspended. + */ extern gfp_t gfp_allowed_mask; extern void pm_restrict_gfp_mask(void); extern void pm_restore_gfp_mask(void); +#ifdef CONFIG_PM_SLEEP +extern bool pm_suspended_storage(void); +#else +static inline bool pm_suspended_storage(void) +{ + return false; +} +#endif /* CONFIG_PM_SLEEP */ + #endif /* __LINUX_GFP_H */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 671e6c94fed77f9fef7b6d56663b8d31c64a8847..3cba4b67203f03fbbe5720d38c324eedb951f8f4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -127,6 +127,13 @@ void pm_restrict_gfp_mask(void) saved_gfp_mask = gfp_allowed_mask; gfp_allowed_mask &= ~GFP_IOFS; } + +bool pm_suspended_storage(void) +{ + if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS) + return false; + return true; +} #endif /* CONFIG_PM_SLEEP */ #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE @@ -1786,12 +1793,25 @@ void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...) static inline int should_alloc_retry(gfp_t gfp_mask, unsigned int order, + unsigned long did_some_progress, unsigned long pages_reclaimed) { /* Do not loop if specifically requested */ if (gfp_mask & __GFP_NORETRY) return 0; + /* Always retry if specifically requested */ + if (gfp_mask & __GFP_NOFAIL) + return 1; + + /* + * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim + * making forward progress without invoking OOM. Suspend also disables + * storage devices so kswapd will not help. Bail if we are suspending. + */ + if (!did_some_progress && pm_suspended_storage()) + return 0; + /* * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER * means __GFP_NOFAIL, but that may not be true in other @@ -1810,13 +1830,6 @@ should_alloc_retry(gfp_t gfp_mask, unsigned int order, if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order)) return 1; - /* - * Don't let big-order allocations loop unless the caller - * explicitly requests that. - */ - if (gfp_mask & __GFP_NOFAIL) - return 1; - return 0; } @@ -2209,7 +2222,8 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, /* Check if we should retry the allocation */ pages_reclaimed += did_some_progress; - if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) { + if (should_alloc_retry(gfp_mask, order, did_some_progress, + pages_reclaimed)) { /* Wait for some write requests to complete then retry */ wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50); goto rebalance; diff --git a/mm/swapfile.c b/mm/swapfile.c index b1cd120607230b0770c35e0823d6389782ae734a..9520592d4231e421ca15b160d8118f4cfa4a4d84 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -667,10 +667,10 @@ int try_to_free_swap(struct page *page) * original page might be freed under memory pressure, then * later read back in from swap, now with the wrong data. * - * Hibernation clears bits from gfp_allowed_mask to prevent - * memory reclaim from writing to disk, so check that here. + * Hibration suspends storage while it is writing the image + * to disk so check that here. */ - if (!(gfp_allowed_mask & __GFP_IO)) + if (pm_suspended_storage()) return 0; delete_from_swap_cache(page);