On Fri 20-06-14 16:24:49, Johannes Weiner wrote: [...] > From cd48b73fdca9e23aa21f65e9af1f850dbac5ab8e Mon Sep 17 00:00:00 2001 > From: Johannes Weiner <hannes@xxxxxxxxxxx> > Date: Wed, 11 Jun 2014 12:53:59 -0400 > Subject: [patch] mm: vmscan: rework compaction-ready signaling in direct > reclaim > > Page reclaim for a higher-order page runs until compaction is ready, > then aborts and signals this situation through the return value of > shrink_zones(). This is an oddly specific signal to encode in the > return value of shrink_zones(), though, and can be quite confusing. > > Introduce sc->compaction_ready and signal the compactability of the > zones out-of-band to free up the return value of shrink_zones() for > actual zone reclaimability. > > Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> > Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Very nice. It will help me to get rid off additional hacks for the min_limit for memcg. Thanks! One question below [...] > @@ -2500,12 +2492,15 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, > vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup, > sc->priority); > sc->nr_scanned = 0; > - aborted_reclaim = shrink_zones(zonelist, sc); > + shrink_zones(zonelist, sc); > > total_scanned += sc->nr_scanned; > if (sc->nr_reclaimed >= sc->nr_to_reclaim) > goto out; > > + if (sc->compaction_ready) > + goto out; > + > /* > * If we're getting trouble reclaiming, start doing > * writepage even in laptop mode. > @@ -2526,7 +2521,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, > WB_REASON_TRY_TO_FREE_PAGES); > sc->may_writepage = 1; > } > - } while (--sc->priority >= 0 && !aborted_reclaim); > + } while (--sc->priority >= 0); > > out: > delayacct_freepages_end(); It is not entirely clear to me why we do not need to check and wake up flusher threads anymore? -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>