Merge branch 'linus' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 16 insertions, 4 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 35fdde041f5c..0b9f577b1a2a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2170,6 +2170,18 @@ static inline void boost_watermark(struct zone *zone)
 
 	max_boost = mult_frac(zone->_watermark[WMARK_HIGH],
 			watermark_boost_factor, 10000);
+
+	/*
+	 * high watermark may be uninitialised if fragmentation occurs
+	 * very early in boot so do not boost. We do not fall
+	 * through and boost by pageblock_nr_pages as failing
+	 * allocations that early means that reclaim is not going
+	 * to help and it may even be impossible to reclaim the
+	 * boosted watermark resulting in a hang.
+	 */
+	if (!max_boost)
+		return;
+
 	max_boost = max(pageblock_nr_pages, max_boost);
 
 	zone->watermark_boost = min(zone->watermark_boost + pageblock_nr_pages,
@@ -4675,11 +4687,11 @@ refill:
 		/* Even if we own the page, we do not use atomic_set().
 		 * This would break get_page_unless_zero() users.
 		 */
-		page_ref_add(page, size - 1);
+		page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE);
 
 		/* reset page count bias and offset to start of new frag */
 		nc->pfmemalloc = page_is_pfmemalloc(page);
-		nc->pagecnt_bias = size;
+		nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
 		nc->offset = size;
 	}
 
@@ -4695,10 +4707,10 @@ refill:
 		size = nc->size;
 #endif
 		/* OK, page count is 0, we can safely set it */
-		set_page_count(page, size);
+		set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1);
 
 		/* reset page count bias and offset to start of new frag */
-		nc->pagecnt_bias = size;
+		nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1;
 		offset = size - fragsz;
 	}