Andrey, could you please clarify, is it required for vz8 too?
On 10/5/20 4:21 PM, Andrey Ryabinin wrote: > __alloc_pages_slowpath relies on the direct reclaim and did_some_progress > as an indicator that it makes sense to retry allocation rather than > declaring OOM. shrink_zones checks if all zones reclaimable and if > shrink_zone didn't make any progress it prevents from a premature OOM > killer invocation by reporting the progress. > This might happen if the LRU is full of dirty or writeback pages > and direct reclaim cannot clean those up. > > zone_reclaimable allows to rescan the reclaimable lists several times > and restart if a page is freed. This is really subtle behavior and it > might lead to a livelock when a single freed page keeps allocator > looping but the current task will not be able to allocate that single > page. OOM killer would be more appropriate than looping without any > progress for unbounded amount of time. > > Report no progress even if zones are reclaimable as OOM is more appropiate > in that case. > > https://jira.sw.ru/browse/PSBM-104900 > Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> > --- > mm/vmscan.c | 24 ------------------------ > 1 file changed, 24 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 13ae9bd1e92e..85622f235e78 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2952,26 +2952,6 @@ static void snapshot_refaults(struct mem_cgroup > *root_memcg, struct zone *zone) > } while ((memcg = mem_cgroup_iter(root_memcg, memcg, NULL))); > } > > -/* All zones in zonelist are unreclaimable? */ > -static bool all_unreclaimable(struct zonelist *zonelist, > - struct scan_control *sc) > -{ > - struct zoneref *z; > - struct zone *zone; > - > - for_each_zone_zonelist_nodemask(zone, z, zonelist, > - gfp_zone(sc->gfp_mask), sc->nodemask) { > - if (!populated_zone(zone)) > - continue; > - if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) > - continue; > - if (zone_reclaimable(zone)) > - return false; > - } > - > - return true; > -} > - > static void shrink_tcrutches(struct scan_control *scan_ctrl) > { > int nid; > @@ -3097,10 +3077,6 @@ out: > goto retry; > } > > - /* top priority shrink_zones still had more to do? don't OOM, then */ > - if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc)) > - return 1; > - > return 0; > } > > _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
