From: Mel Gorman <mgorman@techsingularity.net>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>, Rik van Riel <riel@surriel.com>,
Johannes Weiner <hannes@cmpxchg.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 12/27] mm, vmscan: Make shrink_node decisions more node-centric
Date: Thu, 16 Jun 2016 15:47:52 +0100 [thread overview]
Message-ID: <20160616144752.GI1868@techsingularity.net> (raw)
In-Reply-To: <a411d98e-acfb-9658-22b1-4bbefb1e00d7@suse.cz>
On Thu, Jun 16, 2016 at 03:35:15PM +0200, Vlastimil Babka wrote:
> On 06/09/2016 08:04 PM, Mel Gorman wrote:
> >Earlier patches focused on having direct reclaim and kswapd use data that
> >is node-centric for reclaiming but shrink_node() itself still uses too much
> >zone information. This patch removes unnecessary zone-based information
> >with the most important decision being whether to continue reclaim or
> >not. Some memcg APIs are adjusted as a result even though memcg itself
> >still uses some zone information.
> >
> >Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
>
> [...]
>
> >@@ -2372,21 +2374,27 @@ static inline bool should_continue_reclaim(struct zone *zone,
> > * inactive lists are large enough, continue reclaiming
> > */
> > pages_for_compaction = (2UL << sc->order);
> >- inactive_lru_pages = node_page_state(zone->zone_pgdat, NR_INACTIVE_FILE);
> >+ inactive_lru_pages = node_page_state(pgdat, NR_INACTIVE_FILE);
> > if (get_nr_swap_pages() > 0)
> >- inactive_lru_pages += node_page_state(zone->zone_pgdat, NR_INACTIVE_ANON);
> >+ inactive_lru_pages += node_page_state(pgdat, NR_INACTIVE_ANON);
> > if (sc->nr_reclaimed < pages_for_compaction &&
> > inactive_lru_pages > pages_for_compaction)
> > return true;
> >
> > /* If compaction would go ahead or the allocation would succeed, stop */
> >- switch (compaction_suitable(zone, sc->order, 0, 0)) {
> >- case COMPACT_PARTIAL:
> >- case COMPACT_CONTINUE:
> >- return false;
> >- default:
> >- return true;
> >+ for (z = 0; z <= sc->reclaim_idx; z++) {
> >+ struct zone *zone = &pgdat->node_zones[z];
> >+
> >+ switch (compaction_suitable(zone, sc->order, 0, 0)) {
>
> Using 0 for classzone_idx here was sort of OK when each zone was reclaimed
> separately, as a Normal allocation not passing appropriate classzone_idx
> (and thus subtracting lowmem reserve from free pages) means that a false
> COMPACT_PARTIAL (or COMPACT_CONTINUE) could be returned for e.g. DMA zone.
> It means a premature end of reclaim for this single zone, which is
> relatively small anyway, so no big deal (and we might avoid useless
> over-reclaim, when even reclaiming everything wouldn't get us above the
> lowmem_reserve).
>
> But in node-centric reclaim, such premature "return false" from a DMA zone
> stops reclaiming the whole node. So I think we should involve the real
> classzone_idx here.
>
Fair point although for compaction, it'll occur for a marginal corner
case. Premature allowed compaction for ZONE_DMA is unfortunate but
bizarre to think there would be a high-order allocation restricted to
just that zone too.
I'll pass in sc->reclaim_idx as it represents the allocating order. That
highlights that direct reclaim was not setting reclaim_idx but that's
been corrected.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2016-06-16 14:47 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-09 18:04 [PATCH 00/27] Move LRU page reclaim from zones to nodes v6 Mel Gorman
2016-06-09 18:04 ` [PATCH 01/27] mm, vmstat: Add infrastructure for per-node vmstats Mel Gorman
2016-06-10 13:31 ` Vlastimil Babka
2016-06-10 13:47 ` Mel Gorman
2016-06-13 17:26 ` Christoph Lameter
2016-06-14 14:25 ` Mel Gorman
2016-06-09 18:04 ` [PATCH 02/27] mm, vmscan: Move lru_lock to the node Mel Gorman
2016-06-10 16:39 ` Vlastimil Babka
2016-06-10 17:48 ` Peter Zijlstra
2016-06-14 14:41 ` Mel Gorman
2016-06-09 18:04 ` [PATCH 03/27] mm, vmscan: Move LRU lists to node Mel Gorman
2016-06-10 18:00 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 04/27] mm, vmscan: Begin reclaiming pages on a per-node basis Mel Gorman
2016-06-15 12:52 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 05/27] mm, vmscan: Have kswapd only scan based on the highest requested zone Mel Gorman
2016-06-15 13:13 ` Vlastimil Babka
2016-06-16 7:44 ` Mel Gorman
2016-06-09 18:04 ` [PATCH 06/27] mm, vmscan: Make kswapd reclaim in terms of nodes Mel Gorman
2016-06-15 14:23 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 07/27] mm, vmscan: Remove balance gap Mel Gorman
2016-06-15 14:28 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 08/27] mm, vmscan: Simplify the logic deciding whether kswapd sleeps Mel Gorman
2016-06-15 15:18 ` Vlastimil Babka
2016-06-16 8:30 ` Mel Gorman
2016-06-16 9:16 ` Mel Gorman
2016-06-09 18:04 ` [PATCH 09/27] mm, vmscan: By default have direct reclaim only shrink once per node Mel Gorman
2016-06-16 8:59 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 10/27] mm, vmscan: Clear congestion, dirty and need for compaction on a per-node basis Mel Gorman
2016-06-16 9:29 ` Vlastimil Babka
2016-06-16 10:29 ` Mel Gorman
2016-06-09 18:04 ` [PATCH 11/27] mm: vmscan: Do not reclaim from kswapd if there is any eligible zone Mel Gorman
2016-06-16 10:08 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 12/27] mm, vmscan: Make shrink_node decisions more node-centric Mel Gorman
2016-06-16 13:35 ` Vlastimil Babka
2016-06-16 14:47 ` Mel Gorman [this message]
2016-06-09 18:04 ` [PATCH 13/27] mm, memcg: Move memcg limit enforcement from zones to nodes Mel Gorman
2016-06-16 15:06 ` Vlastimil Babka
2016-06-16 15:53 ` Mel Gorman
2016-06-09 18:04 ` [PATCH 14/27] mm, workingset: Make working set detection node-aware Mel Gorman
2016-06-16 15:13 ` Vlastimil Babka
2016-06-16 15:56 ` Mel Gorman
2016-06-09 18:04 ` [PATCH 15/27] mm, page_alloc: Consider dirtyable memory in terms of nodes Mel Gorman
2016-06-16 15:45 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 16/27] mm: Move page mapped accounting to the node Mel Gorman
2016-06-16 15:52 ` Vlastimil Babka
2016-06-16 16:04 ` Mel Gorman
2016-06-09 18:04 ` [PATCH 17/27] mm: Rename NR_ANON_PAGES to NR_ANON_MAPPED Mel Gorman
2016-06-17 8:28 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 18/27] mm: Move most file-based accounting to the node Mel Gorman
2016-06-17 8:35 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 19/27] mm: Move vmscan writes and file write " Mel Gorman
2016-06-17 8:51 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 20/27] mm, vmscan: Update classzone_idx if buffer_heads_over_limit Mel Gorman
2016-06-17 8:53 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 21/27] mm, vmscan: Only wakeup kswapd once per node for the requested classzone Mel Gorman
2016-06-17 10:46 ` Vlastimil Babka
2016-06-17 12:03 ` Mel Gorman
2016-06-09 18:04 ` [PATCH 22/27] mm: Convert zone_reclaim to node_reclaim Mel Gorman
2016-06-17 10:55 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 23/27] mm, vmscan: Add classzone information to tracepoints Mel Gorman
2016-06-17 10:57 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 24/27] mm, page_alloc: Remove fair zone allocation policy Mel Gorman
2016-06-17 11:27 ` Vlastimil Babka
2016-06-17 12:07 ` Mel Gorman
2016-06-09 18:04 ` [PATCH 25/27] mm: page_alloc: Cache the last node whose dirty limit is reached Mel Gorman
2016-06-17 11:31 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 26/27] mm: vmstat: Replace __count_zone_vm_events with a zone id equivalent Mel Gorman
2016-06-17 11:36 ` Vlastimil Babka
2016-06-09 18:04 ` [PATCH 27/27] mm: vmstat: Account per-zone stalls and pages skipped during reclaim Mel Gorman
2016-06-17 12:39 ` Vlastimil Babka
-- strict thread matches above, loose matches on Subject: below --
2016-06-21 14:15 [PATCH 00/27] Move LRU page reclaim from zones to nodes v7 Mel Gorman
2016-06-21 14:15 ` [PATCH 12/27] mm, vmscan: Make shrink_node decisions more node-centric Mel Gorman
2016-06-22 13:20 ` Michal Hocko
2016-06-22 15:42 ` Vlastimil Babka
2016-04-15 9:13 [PATCH 00/27] Move LRU page reclaim from zones to nodes v5 Mel Gorman
2016-04-15 9:13 ` [PATCH 12/27] mm, vmscan: Make shrink_node decisions more node-centric Mel Gorman
2016-04-06 11:19 [RFC PATCH 00/27] Move LRU page reclaim from zones to nodes v3 Mel Gorman
2016-04-06 11:20 ` [PATCH 12/27] mm, vmscan: Make shrink_node decisions more node-centric Mel Gorman
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