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 --- mm/page_alloc.c | 36 ++++++++++++++++++++++++++++++++++++ 1 files changed, 36 insertions(+), 0 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e35d06b..05eaa82 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5613,6 +5613,34 @@ static int __alloc_contig_migrate_range(unsigned long start, unsigned long end) return ret; }
+/* + * Trigger memory pressure bump to reclaim some pages in order to be able to + * allocate 'count' pages in single page units. Does similar work as + *__alloc_pages_slowpath() function. + */ +static int __reclaim_pages(struct zone *zone, gfp_t gfp_mask, int count) +{ + enum zone_type high_zoneidx = gfp_zone(gfp_mask); + struct zonelist *zonelist = node_zonelist(0, gfp_mask); + int did_some_progress = 0; + int order = 1; + unsigned long watermark; + + /* Obey watermarks as if the page was being allocated */ + watermark = low_wmark_pages(zone) + count; + while (!zone_watermark_ok(zone, 0, watermark, 0, 0)) { + wake_all_kswapd(order, zonelist, high_zoneidx, zone_idx(zone)); + + did_some_progress = __perform_reclaim(gfp_mask, order, zonelist, + NULL); + if (!did_some_progress) { + /* Exhausted what can be done so it's blamo time */ + out_of_memory(zonelist, gfp_mask, order, NULL); + } + } + return count; +} + /** * alloc_contig_range() -- tries to allocate given range of pages * @start: start PFN to allocate @@ -5707,6 +5735,14 @@ int alloc_contig_range(unsigned long start, unsigned long end, goto done; }
+ /* + * Reclaim enough pages to make sure that contiguous allocation + * will not starve the system. + */ + __reclaim_pages(page_zone(pfn_to_page(outer_start)), + GFP_HIGHUSER_MOVABLE, end-start); + + /* Grab isolated pages from freelists. */ outer_end = isolate_freepages_range(outer_start, end); if (!outer_end) { ret = -EBUSY;