diff options
| -rw-r--r-- | mm/page_alloc.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0df3c089d3af..f3e0c69a97b7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3555,6 +3555,17 @@ retry_cpuset: no_progress_loops = 0; compact_priority = DEF_COMPACT_PRIORITY; cpuset_mems_cookie = read_mems_allowed_begin(); + /* + * We need to recalculate the starting point for the zonelist iterator + * because we might have used different nodemask in the fast path, or + * there was a cpuset modification and we are retrying - otherwise we + * could end up iterating over non-eligible zones endlessly. + */ + ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, + ac->high_zoneidx, ac->nodemask); + if (!ac->preferred_zoneref->zone) + goto nopage; + /* * The fast path uses conservative alloc_flags to succeed only until @@ -3715,6 +3726,13 @@ retry: &compaction_retries)) goto retry; + /* + * It's possible we raced with cpuset update so the OOM would be + * premature (see below the nopage: label for full explanation). + */ + if (read_mems_allowed_retry(cpuset_mems_cookie)) + goto retry_cpuset; + /* Reclaim has failed us, start killing things */ page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress); if (page) @@ -3728,10 +3746,11 @@ retry: nopage: /* - * When updating a task's mems_allowed, it is possible to race with - * parallel threads in such a way that an allocation can fail while - * the mask is being updated. If a page allocation is about to fail, - * check if the cpuset changed during allocation and if so, retry. + * When updating a task's mems_allowed or mempolicy nodemask, it is + * possible to race with parallel threads in such a way that our + * allocation can fail while the mask is being updated. If we are about + * to fail, check if the cpuset changed during allocation and if so, + * retry. */ if (read_mems_allowed_retry(cpuset_mems_cookie)) goto retry_cpuset; @@ -3822,15 +3841,9 @@ no_zone: /* * Restore the original nodemask if it was potentially replaced with * &cpuset_current_mems_allowed to optimize the fast-path attempt. - * Also recalculate the starting point for the zonelist iterator or - * we could end up iterating over non-eligible zones endlessly. */ - if (unlikely(ac.nodemask != nodemask)) { + if (unlikely(ac.nodemask != nodemask)) ac.nodemask = nodemask; - ac.preferred_zoneref = first_zones_zonelist(ac.zonelist, - ac.high_zoneidx, ac.nodemask); - /* If we have NULL preferred zone, slowpath wll handle that */ - } page = __alloc_pages_slowpath(alloc_mask, order, &ac); |