From: Dave Chinner <david@fromorbit.com>
To: Mel Gorman <mgorman@suse.de>
Cc: Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>, XFS <xfs@oss.sgi.com>,
Christoph Hellwig <hch@infradead.org>,
Johannes Weiner <jweiner@redhat.com>,
Wu Fengguang <fengguang.wu@intel.com>, Jan Kara <jack@suse.cz>,
Rik van Riel <riel@redhat.com>,
Minchan Kim <minchan.kim@gmail.com>
Subject: Re: [RFC PATCH 0/8] Reduce filesystem writeback from page reclaim v2
Date: Tue, 26 Jul 2011 21:20:55 +1000 [thread overview]
Message-ID: <20110726112055.GC8048@dastard> (raw)
In-Reply-To: <1311265730-5324-1-git-send-email-mgorman@suse.de>
On Thu, Jul 21, 2011 at 05:28:42PM +0100, Mel Gorman wrote:
> Warning: Long post with lots of figures. If you normally drink coffee
> and you don't have a cup, get one or you may end up with a case of
> keyboard face.
[snip]
> Overall, having kswapd avoiding writes does improve performance
> which is not a surprise. Dave asked "do we even need IO at all from
> reclaim?". On NUMA machines, the answer is "yes" unless the VM can
> wake the flusher thread to clean a specific node.
Great answer, Mel. ;)
> When kswapd never
> writes, processes can stall for significant periods of time waiting on
> flushers to clean the correct pages. If all writing is to be deferred
> to flushers, it must ensure that many writes on one node would not
> starve requests for cleaning pages on another node.
Ok, so that's a direction we need to work towards, then.
> I'm currently of the opinion that we should consider merging patches
> 1-7 and discuss what is required before merging. It can be tackled
> later how the flushers can prioritise writing of pages belonging to
> a particular zone before disabling all writes from reclaim.
Sounds reasonable to me.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
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next prev parent reply other threads:[~2011-07-26 11:21 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-21 16:28 [RFC PATCH 0/8] Reduce filesystem writeback from page reclaim v2 Mel Gorman
2011-07-21 16:28 ` [PATCH 1/8] mm: vmscan: Do not writeback filesystem pages in direct reclaim Mel Gorman
2011-07-31 15:06 ` Minchan Kim
2011-08-02 11:21 ` Mel Gorman
2011-07-21 16:28 ` [PATCH 2/8] xfs: Warn if direct reclaim tries to writeback pages Mel Gorman
2011-07-24 11:32 ` Christoph Hellwig
2011-07-25 8:19 ` Mel Gorman
2011-07-21 16:28 ` [PATCH 3/8] ext4: " Mel Gorman
2011-08-03 10:58 ` Johannes Weiner
2011-08-03 11:06 ` Johannes Weiner
2011-08-03 13:44 ` Mel Gorman
2011-08-03 14:00 ` Johannes Weiner
2011-08-03 14:18 ` Christoph Hellwig
2011-08-03 14:35 ` Mel Gorman
2011-07-21 16:28 ` [PATCH 4/8] btrfs: " Mel Gorman
2011-08-03 11:10 ` Johannes Weiner
2011-08-03 13:45 ` Mel Gorman
2011-07-21 16:28 ` [PATCH 5/8] mm: vmscan: Do not writeback filesystem pages in kswapd except in high priority Mel Gorman
2011-07-31 15:11 ` Minchan Kim
2011-07-21 16:28 ` [PATCH 6/8] mm: vmscan: Throttle reclaim if encountering too many dirty pages under writeback Mel Gorman
2011-07-31 15:17 ` Minchan Kim
2011-08-03 11:19 ` Johannes Weiner
2011-08-03 13:56 ` Mel Gorman
2011-07-21 16:28 ` [PATCH 7/8] mm: vmscan: Immediately reclaim end-of-LRU dirty pages when writeback completes Mel Gorman
2011-07-22 12:53 ` Peter Zijlstra
2011-07-22 13:23 ` Mel Gorman
2011-07-31 15:24 ` Minchan Kim
2011-08-02 11:25 ` Mel Gorman
2011-08-03 11:26 ` Johannes Weiner
2011-08-03 13:57 ` Mel Gorman
2011-07-21 16:28 ` [PATCH 8/8] mm: vmscan: Do not writeback filesystem pages from kswapd Mel Gorman
2011-07-22 12:57 ` Peter Zijlstra
2011-07-22 13:31 ` Mel Gorman
2011-08-03 11:37 ` Johannes Weiner
2011-08-03 13:58 ` Mel Gorman
2011-07-26 11:20 ` Dave Chinner [this message]
2011-07-27 4:32 ` [RFC PATCH 0/8] Reduce filesystem writeback from page reclaim v2 Minchan Kim
2011-07-27 7:37 ` Mel Gorman
2011-07-27 16:18 ` Minchan Kim
2011-07-28 11:38 ` Mel Gorman
2011-07-29 9:48 ` Minchan Kim
2011-07-29 9:50 ` Minchan Kim
2011-07-29 13:41 ` Andrew Lutomirski
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