Merge tag 'mlx5-fixes-2019-10-18' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3334a769eb91e1c1cc374560125c8c64e32da979..ecc3dbad606b04ce690e584e4d6609e85c66173b 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1175,11 +1175,17 @@ static __always_inline bool free_pages_prepare(struct page *page,
                debug_check_no_obj_freed(page_address(page),
                                           PAGE_SIZE << order);
        }
-       arch_free_page(page, order);
        if (want_init_on_free())
                kernel_init_free_pages(page, 1 << order);
 
        kernel_poison_pages(page, 1 << order, 0);
+       /*
+        * arch_free_page() can make the page's contents inaccessible.  s390
+        * does this.  So nothing which can access the page's contents should
+        * happen after this.
+        */
+       arch_free_page(page, order);
+
        if (debug_pagealloc_enabled())
                kernel_map_pages(page, 1 << order, 0);
 
@@ -4467,6 +4473,30 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
                if (page)
                        goto got_pg;
 
+                if (order >= pageblock_order && (gfp_mask & __GFP_IO) &&
+                    !(gfp_mask & __GFP_RETRY_MAYFAIL)) {
+                       /*
+                        * If allocating entire pageblock(s) and compaction
+                        * failed because all zones are below low watermarks
+                        * or is prohibited because it recently failed at this
+                        * order, fail immediately unless the allocator has
+                        * requested compaction and reclaim retry.
+                        *
+                        * Reclaim is
+                        *  - potentially very expensive because zones are far
+                        *    below their low watermarks or this is part of very
+                        *    bursty high order allocations,
+                        *  - not guaranteed to help because isolate_freepages()
+                        *    may not iterate over freed pages as part of its
+                        *    linear scan, and
+                        *  - unlikely to make entire pageblocks free on its
+                        *    own.
+                        */
+                       if (compact_result == COMPACT_SKIPPED ||
+                           compact_result == COMPACT_DEFERRED)
+                               goto nopage;
+               }
+
                /*
                 * Checks for costly allocations with __GFP_NORETRY, which
                 * includes THP page fault allocations