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-rw-r--r--mm/backing-dev.c20
-rw-r--r--mm/page_alloc.c41
2 files changed, 40 insertions, 21 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 0c6317b7db38..ed173b8ae8f2 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -957,9 +957,8 @@ EXPORT_SYMBOL(congestion_wait);
* jiffies for either a BDI to exit congestion of the given @sync queue
* or a write to complete.
*
- * In the absence of zone congestion, a short sleep or a cond_resched is
- * performed to yield the processor and to allow other subsystems to make
- * a forward progress.
+ * In the absence of zone congestion, cond_resched() is called to yield
+ * the processor if necessary but otherwise does not sleep.
*
* The return value is 0 if the sleep is for the full timeout. Otherwise,
* it is the number of jiffies that were still remaining when the function
@@ -979,20 +978,7 @@ long wait_iff_congested(struct zone *zone, int sync, long timeout)
*/
if (atomic_read(&nr_wb_congested[sync]) == 0 ||
!test_bit(ZONE_CONGESTED, &zone->flags)) {
-
- /*
- * Memory allocation/reclaim might be called from a WQ
- * context and the current implementation of the WQ
- * concurrency control doesn't recognize that a particular
- * WQ is congested if the worker thread is looping without
- * ever sleeping. Therefore we have to do a short sleep
- * here rather than calling cond_resched().
- */
- if (current->flags & PF_WQ_WORKER)
- schedule_timeout_uninterruptible(1);
- else
- cond_resched();
-
+ cond_resched();
/* In case we scheduled, work out time remaining */
ret = timeout - (jiffies - start);
if (ret < 0)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fa39efc3a692..f51c302126a1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3436,8 +3436,9 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order,
for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
ac->nodemask) {
unsigned long available;
+ unsigned long reclaimable;
- available = zone_reclaimable_pages(zone);
+ available = reclaimable = zone_reclaimable_pages(zone);
available -= DIV_ROUND_UP(no_progress_loops * available,
MAX_RECLAIM_RETRIES);
available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
@@ -3447,9 +3448,41 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order,
* available?
*/
if (__zone_watermark_ok(zone, order, min_wmark_pages(zone),
- ac->high_zoneidx, alloc_flags, available)) {
- /* Wait for some write requests to complete then retry */
- wait_iff_congested(zone, BLK_RW_ASYNC, HZ/50);
+ ac_classzone_idx(ac), alloc_flags, available)) {
+ /*
+ * If we didn't make any progress and have a lot of
+ * dirty + writeback pages then we should wait for
+ * an IO to complete to slow down the reclaim and
+ * prevent from pre mature OOM
+ */
+ if (!did_some_progress) {
+ unsigned long writeback;
+ unsigned long dirty;
+
+ writeback = zone_page_state_snapshot(zone,
+ NR_WRITEBACK);
+ dirty = zone_page_state_snapshot(zone, NR_FILE_DIRTY);
+
+ if (2*(writeback + dirty) > reclaimable) {
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ return true;
+ }
+ }
+
+ /*
+ * Memory allocation/reclaim might be called from a WQ
+ * context and the current implementation of the WQ
+ * concurrency control doesn't recognize that
+ * a particular WQ is congested if the worker thread is
+ * looping without ever sleeping. Therefore we have to
+ * do a short sleep here rather than calling
+ * cond_resched().
+ */
+ if (current->flags & PF_WQ_WORKER)
+ schedule_timeout_uninterruptible(1);
+ else
+ cond_resched();
+
return true;
}
}