mm: trigger page reclaim in alloc_contig_range() to stabilise watermarks

alloc_contig_range() performs memory allocation so it also should keep
track on keeping the correct level of memory watermarks. This commit adds
a call to *_slowpath style reclaim to grab enough pages to make sure that
the final collection of contiguous pages from freelists will not starve
the system.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Michal Nazarewicz <mina86@mina86.com>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 8c1335f3c3a..26f2040b8b0 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -63,8 +63,10 @@ enum {
 
 #ifdef CONFIG_CMA
 #  define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
+#  define cma_wmark_pages(zone) zone->min_cma_pages
 #else
 #  define is_migrate_cma(migratetype) false
+#  define cma_wmark_pages(zone) 0
 #endif
 
 #define for_each_migratetype_order(order, type) \
@@ -371,6 +373,13 @@ struct zone {
         /* see spanned/present_pages for more description */
         seqlock_t               span_seqlock;
 #endif
+#ifdef CONFIG_CMA
+        /*
+         * CMA needs to increase watermark levels during the allocation
+         * process to make sure that the system is not starved.
+         */
+        unsigned long           min_cma_pages;
+#endif
         struct free_area        free_area[MAX_ORDER];
 
 #ifndef CONFIG_SPARSEMEM