1 files changed, 22 insertions, 5 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6a29ed8e6e60..38e5be65f24e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1513,6 +1513,7 @@ failed:
 #define ALLOC_HARDER            0x10 /* try to alloc harder */
 #define ALLOC_HIGH              0x20 /* __GFP_HIGH set */
 #define ALLOC_CPUSET            0x40 /* check for correct cpuset */
+#define ALLOC_PFMEMALLOC        0x80 /* Caller has PF_MEMALLOC set */
 
 #ifdef CONFIG_FAIL_PAGE_ALLOC
 
@@ -2293,16 +2294,22 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
         } else if (unlikely(rt_task(current)) && !in_interrupt())
                 alloc_flags |= ALLOC_HARDER;
 
-        if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
-                if (!in_interrupt() &&
-                    ((current->flags & PF_MEMALLOC) ||
-                     unlikely(test_thread_flag(TIF_MEMDIE))))
+        if ((current->flags & PF_MEMALLOC) ||
+                        unlikely(test_thread_flag(TIF_MEMDIE))) {
+                alloc_flags |= ALLOC_PFMEMALLOC;
+
+                if (likely(!(gfp_mask & __GFP_NOMEMALLOC)) && !in_interrupt())
                         alloc_flags |= ALLOC_NO_WATERMARKS;
         }
 
         return alloc_flags;
 }
 
+bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
+{
+        return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_PFMEMALLOC);
+}
+
 static inline struct page *
 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
         struct zonelist *zonelist, enum zone_type high_zoneidx,
@@ -2490,10 +2497,18 @@ nopage:
         warn_alloc_failed(gfp_mask, order, NULL);
         return page;
 got_pg:
+        /*
+         * page->pfmemalloc is set when the caller had PFMEMALLOC set or is
+         * been OOM killed. The expectation is that the caller is taking
+         * steps that will free more memory. The caller should avoid the
+         * page being used for !PFMEMALLOC purposes.
+         */
+        page->pfmemalloc = !!(alloc_flags & ALLOC_PFMEMALLOC);
+
         if (kmemcheck_enabled)
                 kmemcheck_pagealloc_alloc(page, order, gfp_mask);
-        return page;
 
+        return page;
 }
 
 /*
@@ -2544,6 +2559,8 @@ retry_cpuset:
                 page = __alloc_pages_slowpath(gfp_mask, order,
                                 zonelist, high_zoneidx, nodemask,
                                 preferred_zone, migratetype);
+        else
+                page->pfmemalloc = false;
 
         trace_mm_page_alloc(page, order, gfp_mask, migratetype);