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authorLinus Torvalds <torvalds@linux-foundation.org>2016-06-04 10:51:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-06-04 10:51:29 -0700
commitd46d0256cd030f196185078a4a8863563425b624 (patch)
treef72264009d1e979bd5f24b1b3e5fc70172446db9 /mm/page_alloc.c
parent8c52b6dcdd1994ad0d2672e43c8d975d5c8195c3 (diff)
parente46e7b77c9096eb2f4d6bcb9ca0b64c9338465ee (diff)
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Merge branch 'akpm' (patches from Andrew)
Merge various fixes from Andrew Morton: "10 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm, page_alloc: recalculate the preferred zoneref if the context can ignore memory policies mm, page_alloc: reset zonelist iterator after resetting fair zone allocation policy mm, oom_reaper: do not use siglock in try_oom_reaper() mm, page_alloc: prevent infinite loop in buffered_rmqueue() checkpatch: reduce git commit description style false positives mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup memcg: add RCU locking around css_for_each_descendant_pre() in memcg_offline_kmem() mm: check the return value of lookup_page_ext for all call sites kdump: fix dmesg gdbmacro to work with record based printk mm: fix overflow in vm_map_ram()
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r--mm/page_alloc.c39
1 files changed, 28 insertions, 11 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f8f3bfc435ee..6903b695ebae 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -656,6 +656,9 @@ static inline void set_page_guard(struct zone *zone, struct page *page,
return;
page_ext = lookup_page_ext(page);
+ if (unlikely(!page_ext))
+ return;
+
__set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
INIT_LIST_HEAD(&page->lru);
@@ -673,6 +676,9 @@ static inline void clear_page_guard(struct zone *zone, struct page *page,
return;
page_ext = lookup_page_ext(page);
+ if (unlikely(!page_ext))
+ return;
+
__clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
set_page_private(page, 0);
@@ -2609,11 +2615,12 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
page = list_last_entry(list, struct page, lru);
else
page = list_first_entry(list, struct page, lru);
- } while (page && check_new_pcp(page));
- __dec_zone_state(zone, NR_ALLOC_BATCH);
- list_del(&page->lru);
- pcp->count--;
+ __dec_zone_state(zone, NR_ALLOC_BATCH);
+ list_del(&page->lru);
+ pcp->count--;
+
+ } while (check_new_pcp(page));
} else {
/*
* We most definitely don't want callers attempting to
@@ -3023,6 +3030,7 @@ reset_fair:
apply_fair = false;
fair_skipped = false;
reset_alloc_batches(ac->preferred_zoneref->zone);
+ z = ac->preferred_zoneref;
goto zonelist_scan;
}
@@ -3596,6 +3604,17 @@ retry:
*/
alloc_flags = gfp_to_alloc_flags(gfp_mask);
+ /*
+ * Reset the zonelist iterators if memory policies can be ignored.
+ * These allocations are high priority and system rather than user
+ * orientated.
+ */
+ if ((alloc_flags & ALLOC_NO_WATERMARKS) || !(alloc_flags & ALLOC_CPUSET)) {
+ ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
+ ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
+ ac->high_zoneidx, ac->nodemask);
+ }
+
/* This is the last chance, in general, before the goto nopage. */
page = get_page_from_freelist(gfp_mask, order,
alloc_flags & ~ALLOC_NO_WATERMARKS, ac);
@@ -3604,12 +3623,6 @@ retry:
/* Allocate without watermarks if the context allows */
if (alloc_flags & ALLOC_NO_WATERMARKS) {
- /*
- * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
- * the allocation is high priority and these type of
- * allocations are system rather than user orientated
- */
- ac->zonelist = node_zonelist(numa_node_id(), gfp_mask);
page = get_page_from_freelist(gfp_mask, order,
ALLOC_NO_WATERMARKS, ac);
if (page)
@@ -3808,7 +3821,11 @@ retry_cpuset:
/* Dirty zone balancing only done in the fast path */
ac.spread_dirty_pages = (gfp_mask & __GFP_WRITE);
- /* The preferred zone is used for statistics later */
+ /*
+ * The preferred zone is used for statistics but crucially it is
+ * also used as the starting point for the zonelist iterator. It
+ * may get reset for allocations that ignore memory policies.
+ */
ac.preferred_zoneref = first_zones_zonelist(ac.zonelist,
ac.high_zoneidx, ac.nodemask);
if (!ac.preferred_zoneref) {