Messages in this thread | | | Date | Fri, 26 Jul 2019 09:12:25 +0100 | From | Mel Gorman <> | Subject | Re: [RFC PATCH 1/3] mm, reclaim: make should_continue_reclaim perform dryrun detection |
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> From: Hillf Danton <hdanton@sina.com> > Subject: [RFC PATCH 1/3] mm, reclaim: make should_continue_reclaim perform dryrun detection > > Address the issue of should_continue_reclaim continuing true too often > for __GFP_RETRY_MAYFAIL attempts when !nr_reclaimed and nr_scanned. > This could happen during hugetlb page allocation causing stalls for > minutes or hours. > > We can stop reclaiming pages if compaction reports it can make a progress. > A code reshuffle is needed to do that. And it has side-effects, however, > with allocation latencies in other cases but that would come at the cost > of potential premature reclaim which has consequences of itself. > > We can also bail out of reclaiming pages if we know that there are not > enough inactive lru pages left to satisfy the costly allocation. > > We can give up reclaiming pages too if we see dryrun occur, with the > certainty of plenty of inactive pages. IOW with dryrun detected, we are > sure we have reclaimed as many pages as we could. > > Cc: Mike Kravetz <mike.kravetz@oracle.com> > Cc: Mel Gorman <mgorman@suse.de> > Cc: Michal Hocko <mhocko@kernel.org> > Cc: Vlastimil Babka <vbabka@suse.cz> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Signed-off-by: Hillf Danton <hdanton@sina.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Thanks Hillf
-- Mel Gorman SUSE Labs
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