From: Chris Friesen <chris.friesen@windriver.com>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Josh Durgin <josh.durgin@inktank.com>,
Jeff Cody <jcody@redhat.com>,
Linux Virtualization <virtualization@lists.linux-foundation.org>,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: help? looking for limits on in-flight write operations for virtio-blk
Date: Tue, 26 Aug 2014 23:43:54 -0600 [thread overview]
Message-ID: <53FD701A.4060204@windriver.com> (raw)
In-Reply-To: <53FCA088.7050108@windriver.com>
On 08/26/2014 08:58 AM, Chris Friesen wrote:
> What I'd like to see (and may take a stab at implementing) is a cap on
> either inflight bytes or inflight IOPS. One complication is that this
> requires hooking into the completion path to update the stats (and
> possibly unblock the I/O code) when an operation is done.
Well, it looks like I won't be taking a stab at this after all.
It seems that modifying qemu to call mallopt() to set the trim/mmap
thresholds to 128K is enough to minimize the increase in RSS and also
drop it back down after an I/O burst. For now this looks like it should
be sufficient for our purposes.
I'm actually a bit surprised I didn't have to go lower, but it seems to
work for both "dd" and dbench testcases so we'll give it a try.
Chris
prev parent reply other threads:[~2014-08-27 5:43 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-25 19:42 help? looking for limits on in-flight write operations for virtio-blk Chris Friesen
2014-08-26 10:34 ` Stefan Hajnoczi
2014-08-26 14:58 ` Chris Friesen
2014-08-27 5:43 ` Chris Friesen [this message]
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=53FD701A.4060204@windriver.com \
--to=chris.friesen@windriver.com \
--cc=jcody@redhat.com \
--cc=josh.durgin@inktank.com \
--cc=mst@redhat.com \
--cc=stefanha@gmail.com \
--cc=virtualization@lists.linux-foundation.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.