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-rw-r--r--mm/vmscan.c37
1 files changed, 27 insertions, 10 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 48550c66f1f2..cbf84e152f04 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2207,9 +2207,12 @@ static bool pfmemalloc_watermark_ok(pg_data_t *pgdat)
* Throttle direct reclaimers if backing storage is backed by the network
* and the PFMEMALLOC reserve for the preferred node is getting dangerously
* depleted. kswapd will continue to make progress and wake the processes
- * when the low watermark is reached
+ * when the low watermark is reached.
+ *
+ * Returns true if a fatal signal was delivered during throttling. If this
+ * happens, the page allocator should not consider triggering the OOM killer.
*/
-static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist,
+static bool throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist,
nodemask_t *nodemask)
{
struct zone *zone;
@@ -2224,13 +2227,20 @@ static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist,
* processes to block on log_wait_commit().
*/
if (current->flags & PF_KTHREAD)
- return;
+ goto out;
+
+ /*
+ * If a fatal signal is pending, this process should not throttle.
+ * It should return quickly so it can exit and free its memory
+ */
+ if (fatal_signal_pending(current))
+ goto out;
/* Check if the pfmemalloc reserves are ok */
first_zones_zonelist(zonelist, high_zoneidx, NULL, &zone);
pgdat = zone->zone_pgdat;
if (pfmemalloc_watermark_ok(pgdat))
- return;
+ goto out;
/* Account for the throttling */
count_vm_event(PGSCAN_DIRECT_THROTTLE);
@@ -2246,12 +2256,20 @@ static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist,
if (!(gfp_mask & __GFP_FS)) {
wait_event_interruptible_timeout(pgdat->pfmemalloc_wait,
pfmemalloc_watermark_ok(pgdat), HZ);
- return;
+
+ goto check_pending;
}
/* Throttle until kswapd wakes the process */
wait_event_killable(zone->zone_pgdat->pfmemalloc_wait,
pfmemalloc_watermark_ok(pgdat));
+
+check_pending:
+ if (fatal_signal_pending(current))
+ return true;
+
+out:
+ return false;
}
unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
@@ -2273,13 +2291,12 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
.gfp_mask = sc.gfp_mask,
};
- throttle_direct_reclaim(gfp_mask, zonelist, nodemask);
-
/*
- * Do not enter reclaim if fatal signal is pending. 1 is returned so
- * that the page allocator does not consider triggering OOM
+ * Do not enter reclaim if fatal signal was delivered while throttled.
+ * 1 is returned so that the page allocator does not OOM kill at this
+ * point.
*/
- if (fatal_signal_pending(current))
+ if (throttle_direct_reclaim(gfp_mask, zonelist, nodemask))
return 1;
trace_mm_vmscan_direct_reclaim_begin(order,