From: Mark Tinguely <tinguely@sgi.com>
To: Dave Chinner <david@fromorbit.com>
Cc: xfs@oss.sgi.com
Subject: Re: [PATCH 03/18] xfs: Do background CIL flushes via a workqueue
Date: Tue, 17 Apr 2012 12:54:44 -0500 [thread overview]
Message-ID: <4F8DAE64.9060605@sgi.com> (raw)
In-Reply-To: <1334319061-12968-4-git-send-email-david@fromorbit.com>
On 04/13/12 07:10, Dave Chinner wrote:
> From: Dave Chinner<dchinner@redhat.com>
>
> Doing background CIL flushes adds significant latency to whatever
> async transaction that triggers it. To avoid blocking async
> transactions on things like waiting for log buffer IO to complete,
> move the CIL push off into a workqueue. By moving the push work
> into a workqueue, we remove all the latency that the commit adds
> from the foreground transaction commit path. This also means that
> single threaded workloads won't do the CIL push procssing, leaving
> them more CPU to do more async transactions.
>
> To do this, we need to keep track of the sequence number we have
> pushed work for. This avoids having many transaction commits
> attempting to schedule work for the same sequence, and ensures that
> we only ever have one push (background or forced) in progress at a
> time. It also means that we don't need to take the CIL lock in write
> mode to check for potential background push races, which reduces
> lock contention.
>
> To avoid potential issues with "smart" IO schedulers, don't use the
> workqueue for log force triggered flushes. Instead, do them directly
> so that the log IO is done directly by the process issuing the log
> force and so doesn't get stuck on IO elevator queue idling
> incorrectly delaying the log IO from the workqueue.
>
> Signed-off-by: Dave Chinner<dchinner@redhat.com>
> ---
Makes sense.
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
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next prev parent reply other threads:[~2012-04-17 17:54 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-13 12:10 [PATCH 0/18] xfs: current patch queue Dave Chinner
2012-04-13 12:10 ` [PATCH 01/18] xfs: Ensure inode reclaim can run during quotacheck Dave Chinner
2012-04-13 18:01 ` Mark Tinguely
2012-04-29 21:37 ` Christoph Hellwig
2012-04-13 12:10 ` [PATCH 02/18] xfs: pass shutdown method into xfs_trans_ail_delete_bulk Dave Chinner
2012-04-13 17:40 ` Mark Tinguely
2012-04-13 23:04 ` Dave Chinner
2012-04-13 23:38 ` [PATCH 02/18 V2] " Dave Chinner
2012-04-16 18:49 ` Mark Tinguely
2012-04-13 12:10 ` [PATCH 03/18] xfs: Do background CIL flushes via a workqueue Dave Chinner
2012-04-17 17:54 ` Mark Tinguely [this message]
2012-04-17 21:21 ` Ben Myers
2012-04-17 21:49 ` Ben Myers
2012-04-18 1:47 ` Dave Chinner
2012-04-30 1:24 ` Dave Chinner
2012-04-30 6:09 ` Dave Chinner
2012-04-18 1:58 ` Dave Chinner
2012-04-13 12:10 ` [PATCH 04/18] xfs: page type check in writeback only checks last buffer Dave Chinner
2012-04-16 16:15 ` Mark Tinguely
2012-04-29 21:39 ` Christoph Hellwig
2012-04-30 0:29 ` Dave Chinner
2012-04-13 12:10 ` [PATCH 05/18] xfs: Use preallocation for inodes with extsz hints Dave Chinner
2012-04-13 16:45 ` Mark Tinguely
2012-04-16 15:59 ` Mark Tinguely
2012-04-13 12:10 ` [PATCH 06/18] xfs: fix buffer lookup race on allocation failure Dave Chinner
2012-04-13 18:32 ` Mark Tinguely
2012-04-13 12:10 ` [PATCH 07/18] xfs: check for buffer errors before waiting Dave Chinner
2012-04-13 17:56 ` Mark Tinguely
2012-04-13 12:10 ` [PATCH 08/18] xfs: fix incorrect b_offset initialisation Dave Chinner
2012-04-13 12:10 ` [PATCH 09/18] xfs: use kmem_zone_zalloc for buffers Dave Chinner
2012-04-13 12:10 ` [PATCH 10/18] xfs: clean up buffer get/read call API Dave Chinner
2012-04-13 12:10 ` [PATCH 11/18] xfs: kill b_file_offset Dave Chinner
2012-04-13 12:10 ` [PATCH 12/18] xfs: use blocks for counting length of buffers Dave Chinner
2012-04-13 12:10 ` [PATCH 13/18] xfs: use blocks for storing the desired IO size Dave Chinner
2012-04-13 12:10 ` [PATCH 14/18] xfs: kill xfs_buf_btoc Dave Chinner
2012-04-13 12:10 ` [PATCH 15/18] xfs: kill XBF_LOCK Dave Chinner
2012-04-13 21:20 ` Mark Tinguely
2012-04-13 12:10 ` [PATCH 16/18] xfs: kill xfs_read_buf() Dave Chinner
2012-04-13 12:11 ` [PATCH 17/18] xfs: kill XBF_DONTBLOCK Dave Chinner
2012-04-16 14:34 ` Mark Tinguely
2012-04-13 12:11 ` [PATCH 18/18] xfs: use iolock on XFS_IOC_ALLOCSP calls Dave Chinner
2012-04-16 15:10 ` Mark Tinguely
2012-04-16 21:29 ` [PATCH 0/18] xfs: current patch queue Ben Myers
2012-04-17 4:12 ` Dave Chinner
2012-04-17 14:44 ` Ben Myers
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