From: NeilBrown <neilb@suse.de>
To: Mel Gorman <mgorman@suse.de>
Cc: Linux-MM <linux-mm@kvack.org>,
Linux-Netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
David Miller <davem@davemloft.net>,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH 12/13] mm: Throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage
Date: Tue, 26 Apr 2011 22:30:59 +1000 [thread overview]
Message-ID: <20110426223059.10f3edda@notabene.brown> (raw)
In-Reply-To: <1303803414-5937-13-git-send-email-mgorman@suse.de>
On Tue, 26 Apr 2011 08:36:53 +0100 Mel Gorman <mgorman@suse.de> wrote:
> +/*
> + * Throttle direct reclaimers if backing storage is backed by the network
> + * and the PFMEMALLOC reserve for the preferred node is getting dangerously
> + * depleted. kswapd will continue to make progress and wake the processes
> + * when the low watermark is reached
> + */
> +static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist,
> + nodemask_t *nodemask)
> +{
> + struct zone *zone;
> + int high_zoneidx = gfp_zone(gfp_mask);
> + DEFINE_WAIT(wait);
> +
> + /* Check if the pfmemalloc reserves are ok */
> + first_zones_zonelist(zonelist, high_zoneidx, NULL, &zone);
> + prepare_to_wait(&zone->zone_pgdat->pfmemalloc_wait, &wait,
> + TASK_INTERRUPTIBLE);
> + if (pfmemalloc_watermark_ok(zone->zone_pgdat, high_zoneidx))
> + goto out;
> +
> + /* Throttle */
> + do {
> + schedule();
> + finish_wait(&zone->zone_pgdat->pfmemalloc_wait, &wait);
> + prepare_to_wait(&zone->zone_pgdat->pfmemalloc_wait, &wait,
> + TASK_INTERRUPTIBLE);
> + } while (!pfmemalloc_watermark_ok(zone->zone_pgdat, high_zoneidx) &&
> + !fatal_signal_pending(current));
> +
> +out:
> + finish_wait(&zone->zone_pgdat->pfmemalloc_wait, &wait);
> +}
You are doing an interruptible wait, but only checking for fatal signals.
So if a non-fatal signal arrives, you will busy-wait.
So I suspect you want TASK_KILLABLE, so just use:
wait_event_killable(zone->zone_pgdat->pfmemalloc_wait,
pgmemalloc_watermark_ok(zone->zone_pgdata,
high_zoneidx));
(You also have an extraneous call to finish_wait)
NeilBrown
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next prev parent reply other threads:[~2011-04-26 12:31 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-26 7:36 [PATCH 00/13] Swap-over-NBD without deadlocking Mel Gorman
2011-04-26 7:36 ` [PATCH 01/13] mm: Serialize access to min_free_kbytes Mel Gorman
2011-04-26 7:36 ` [PATCH 02/13] mm: sl[au]b: Add knowledge of PFMEMALLOC reserve pages Mel Gorman
2011-04-26 11:15 ` NeilBrown
2011-04-26 11:33 ` Mel Gorman
2011-04-26 12:05 ` NeilBrown
2011-04-26 11:37 ` NeilBrown
2011-04-26 13:59 ` Mel Gorman
2011-04-27 23:21 ` NeilBrown
2011-04-28 9:46 ` Mel Gorman
2011-04-26 7:36 ` [PATCH 03/13] mm: Introduce __GFP_MEMALLOC to allow access to emergency reserves Mel Gorman
2011-04-26 9:49 ` NeilBrown
2011-04-26 10:36 ` Mel Gorman
2011-04-26 10:53 ` NeilBrown
2011-04-26 14:00 ` Mel Gorman
2011-04-26 7:36 ` [PATCH 04/13] mm: allow PF_MEMALLOC from softirq context Mel Gorman
2011-04-26 7:36 ` [PATCH 05/13] mm: Ignore mempolicies when using ALLOC_NO_WATERMARK Mel Gorman
2011-04-26 7:36 ` [PATCH 06/13] net: Introduce sk_allocation() to allow addition of GFP flags depending on the individual socket Mel Gorman
2011-04-26 7:36 ` [PATCH 07/13] netvm: Allow the use of __GFP_MEMALLOC by specific sockets Mel Gorman
2011-04-26 7:36 ` [PATCH 08/13] netvm: Allow skb allocation to use PFMEMALLOC reserves Mel Gorman
2011-04-26 7:36 ` [PATCH 09/13] netvm: Set PF_MEMALLOC as appropriate during SKB processing Mel Gorman
2011-04-26 12:21 ` NeilBrown
2011-04-26 14:10 ` Mel Gorman
2011-04-26 23:22 ` NeilBrown
2011-04-26 7:36 ` [PATCH 10/13] mm: Micro-optimise slab to avoid a function call Mel Gorman
2011-04-26 7:36 ` [PATCH 11/13] nbd: Set SOCK_MEMALLOC for access to PFMEMALLOC reserves Mel Gorman
2011-04-26 7:36 ` [PATCH 12/13] mm: Throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage Mel Gorman
2011-04-26 12:30 ` NeilBrown [this message]
2011-04-26 14:26 ` Mel Gorman
2011-04-26 23:18 ` NeilBrown
2011-04-27 8:36 ` Mel Gorman
2011-04-26 7:36 ` [PATCH 13/13] mm: Account for the number of times direct reclaimers get throttled Mel Gorman
2011-04-26 12:35 ` NeilBrown
2011-04-26 14:26 ` Mel Gorman
2011-04-26 14:23 ` [PATCH 00/13] Swap-over-NBD without deadlocking Peter Zijlstra
2011-04-26 14:46 ` Mel Gorman
2011-04-26 14:50 ` Peter Zijlstra
2011-04-27 8:43 ` Mel Gorman
2011-04-28 13:31 ` Pavel Machek
2011-04-28 13:42 ` Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2011-04-27 16:07 [PATCH 00/13] Swap-over-NBD without deadlocking v3 Mel Gorman
2011-04-27 16:08 ` [PATCH 12/13] mm: Throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage Mel Gorman
2011-04-28 0:22 ` NeilBrown
2011-04-28 10:14 ` Mel Gorman
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