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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 20:50:02 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 20:50:02 -0800 |
commit | e34bac726d27056081d0250c0e173e4b155aa340 (patch) | |
tree | 85607d0b3b185380fb3267866020c6a4372b9298 /mm/page_alloc.c | |
parent | fe6bce8d30a86c693bf7cfbf4759cbafd121289f (diff) | |
parent | 39a0e975c37dee93fa1b8ea5f7eacd1c4c8a586e (diff) | |
download | linux-stable-e34bac726d27056081d0250c0e173e4b155aa340.tar.gz linux-stable-e34bac726d27056081d0250c0e173e4b155aa340.tar.bz2 linux-stable-e34bac726d27056081d0250c0e173e4b155aa340.zip |
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:
- various misc bits
- most of MM (quite a lot of MM material is awaiting the merge of
linux-next dependencies)
- kasan
- printk updates
- procfs updates
- MAINTAINERS
- /lib updates
- checkpatch updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (123 commits)
init: reduce rootwait polling interval time to 5ms
binfmt_elf: use vmalloc() for allocation of vma_filesz
checkpatch: don't emit unified-diff error for rename-only patches
checkpatch: don't check c99 types like uint8_t under tools
checkpatch: avoid multiple line dereferences
checkpatch: don't check .pl files, improve absolute path commit log test
scripts/checkpatch.pl: fix spelling
checkpatch: don't try to get maintained status when --no-tree is given
lib/ida: document locking requirements a bit better
lib/rbtree.c: fix typo in comment of ____rb_erase_color
lib/Kconfig.debug: make CONFIG_STRICT_DEVMEM depend on CONFIG_DEVMEM
MAINTAINERS: add drm and drm/i915 irc channels
MAINTAINERS: add "C:" for URI for chat where developers hang out
MAINTAINERS: add drm and drm/i915 bug filing info
MAINTAINERS: add "B:" for URI where to file bugs
get_maintainer: look for arbitrary letter prefixes in sections
printk: add Kconfig option to set default console loglevel
printk/sound: handle more message headers
printk/btrfs: handle more message headers
printk/kdb: handle more message headers
...
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r-- | mm/page_alloc.c | 75 |
1 files changed, 56 insertions, 19 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3dcc54da5637..f64e7bcb43b7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2058,8 +2058,12 @@ out_unlock: * potentially hurts the reliability of high-order allocations when under * intense memory pressure but failed atomic allocations should be easier * to recover from than an OOM. + * + * If @force is true, try to unreserve a pageblock even though highatomic + * pageblock is exhausted. */ -static void unreserve_highatomic_pageblock(const struct alloc_context *ac) +static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, + bool force) { struct zonelist *zonelist = ac->zonelist; unsigned long flags; @@ -2067,11 +2071,16 @@ static void unreserve_highatomic_pageblock(const struct alloc_context *ac) struct zone *zone; struct page *page; int order; + bool ret; for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx, ac->nodemask) { - /* Preserve at least one pageblock */ - if (zone->nr_reserved_highatomic <= pageblock_nr_pages) + /* + * Preserve at least one pageblock unless memory pressure + * is really high. + */ + if (!force && zone->nr_reserved_highatomic <= + pageblock_nr_pages) continue; spin_lock_irqsave(&zone->lock, flags); @@ -2085,13 +2094,25 @@ static void unreserve_highatomic_pageblock(const struct alloc_context *ac) continue; /* - * It should never happen but changes to locking could - * inadvertently allow a per-cpu drain to add pages - * to MIGRATE_HIGHATOMIC while unreserving so be safe - * and watch for underflows. + * In page freeing path, migratetype change is racy so + * we can counter several free pages in a pageblock + * in this loop althoug we changed the pageblock type + * from highatomic to ac->migratetype. So we should + * adjust the count once. */ - zone->nr_reserved_highatomic -= min(pageblock_nr_pages, - zone->nr_reserved_highatomic); + if (get_pageblock_migratetype(page) == + MIGRATE_HIGHATOMIC) { + /* + * It should never happen but changes to + * locking could inadvertently allow a per-cpu + * drain to add pages to MIGRATE_HIGHATOMIC + * while unreserving so be safe and watch for + * underflows. + */ + zone->nr_reserved_highatomic -= min( + pageblock_nr_pages, + zone->nr_reserved_highatomic); + } /* * Convert to ac->migratetype and avoid the normal @@ -2103,12 +2124,16 @@ static void unreserve_highatomic_pageblock(const struct alloc_context *ac) * may increase. */ set_pageblock_migratetype(page, ac->migratetype); - move_freepages_block(zone, page, ac->migratetype); - spin_unlock_irqrestore(&zone->lock, flags); - return; + ret = move_freepages_block(zone, page, ac->migratetype); + if (ret) { + spin_unlock_irqrestore(&zone->lock, flags); + return ret; + } } spin_unlock_irqrestore(&zone->lock, flags); } + + return false; } /* Remove an element from the buddy allocator from the fallback list */ @@ -2133,7 +2158,8 @@ __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) page = list_first_entry(&area->free_list[fallback_mt], struct page, lru); - if (can_steal) + if (can_steal && + get_pageblock_migratetype(page) != MIGRATE_HIGHATOMIC) steal_suitable_fallback(zone, page, start_migratetype); /* Remove the page from the freelists */ @@ -2192,7 +2218,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, unsigned long count, struct list_head *list, int migratetype, bool cold) { - int i; + int i, alloced = 0; spin_lock(&zone->lock); for (i = 0; i < count; ++i) { @@ -2217,13 +2243,21 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order, else list_add_tail(&page->lru, list); list = &page->lru; + alloced++; if (is_migrate_cma(get_pcppage_migratetype(page))) __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, -(1 << order)); } + + /* + * i pages were removed from the buddy list even if some leak due + * to check_pcp_refill failing so adjust NR_FREE_PAGES based + * on i. Do not confuse with 'alloced' which is the number of + * pages added to the pcp list. + */ __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); spin_unlock(&zone->lock); - return i; + return alloced; } #ifdef CONFIG_NUMA @@ -2534,7 +2568,8 @@ int __isolate_free_page(struct page *page, unsigned int order) struct page *endpage = page + (1 << order) - 1; for (; page < endpage; page += pageblock_nr_pages) { int mt = get_pageblock_migratetype(page); - if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)) + if (!is_migrate_isolate(mt) && !is_migrate_cma(mt) + && mt != MIGRATE_HIGHATOMIC) set_pageblock_migratetype(page, MIGRATE_MOVABLE); } @@ -3305,7 +3340,7 @@ retry: * Shrink them them and try again */ if (!page && !drained) { - unreserve_highatomic_pageblock(ac); + unreserve_highatomic_pageblock(ac, false); drain_all_pages(NULL); drained = true; goto retry; @@ -3422,8 +3457,10 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order, * Make sure we converge to OOM if we cannot make any progress * several times in the row. */ - if (*no_progress_loops > MAX_RECLAIM_RETRIES) - return false; + if (*no_progress_loops > MAX_RECLAIM_RETRIES) { + /* Before OOM, exhaust highatomic_reserve */ + return unreserve_highatomic_pageblock(ac, true); + } /* * Keep reclaiming pages while there is a chance this will lead |