From: Christoph Hellwig <hch@lst.de>
To: Amir Goldstein <amir73il@gmail.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>,
Dave Chinner <david@fromorbit.com>,
linux-xfs <linux-xfs@vger.kernel.org>,
Christoph Hellwig <hch@lst.de>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [QUESTION] Long read latencies on mixed rw buffered IO
Date: Mon, 25 Mar 2019 19:02:13 +0100 [thread overview]
Message-ID: <20190325180213.GA31766@lst.de> (raw)
In-Reply-To: <CAOQ4uxjh2w3PeyftwJS5djndVp0kSRwf9ki1FUMRqCU9H+uDTg@mail.gmail.com>
On Mon, Mar 25, 2019 at 07:56:33PM +0200, Amir Goldstein wrote:
> Sure, let's give that a shot. But allow me to stay skeptical, because
> I don't think there is a one-size-fits-all solution.
> If application doesn't need >4K atomicity and xfs imposes file-wide
> read locks, there is bound to exist a workload where ext4 can guaranty
> lower latencies than xfs.
>
> Then again, if we fix rw_semaphore to do a good enough job for my
> workload, I may not care about those worst case workloads...
Downgrading these long standing guarantees is simply not an option.
Not quite sure what the I/O pattern of your workload is, but if it
is reads from other regions than you write to you should look into
implementing range locks.
next prev parent reply other threads:[~2019-03-25 18:02 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAOQ4uxi0pGczXBX7GRAFs88Uw0n1ERJZno3JSeZR71S1dXg+2w@mail.gmail.com>
[not found] ` <20190325001044.GA23020@dastard>
2019-03-25 7:49 ` [QUESTION] Long read latencies on mixed rw buffered IO Amir Goldstein
2019-03-25 15:47 ` Darrick J. Wong
2019-03-25 16:41 ` Matthew Wilcox
2019-03-25 17:30 ` Amir Goldstein
2019-03-25 18:22 ` Matthew Wilcox
2019-03-25 19:18 ` Amir Goldstein
2019-03-25 19:40 ` Matthew Wilcox
2019-03-25 19:57 ` Amir Goldstein
2019-03-25 23:48 ` Dave Chinner
2019-03-26 3:44 ` Amir Goldstein
2019-03-27 1:29 ` Dave Chinner
2019-03-25 17:56 ` Amir Goldstein
2019-03-25 18:02 ` Christoph Hellwig [this message]
2019-03-25 18:44 ` Amir Goldstein
2019-03-25 23:43 ` Dave Chinner
2019-03-26 4:36 ` Amir Goldstein
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190325180213.GA31766@lst.de \
--to=hch@lst.de \
--cc=amir73il@gmail.com \
--cc=darrick.wong@oracle.com \
--cc=david@fromorbit.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-xfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).