From: "Theodore Ts'o" <tytso@mit.edu>
To: Christoph Hellwig <hch@infradead.org>
Cc: Linux Kernel Developers List <linux-kernel@vger.kernel.org>,
Venkatesh Srinivas <venkateshs@google.com>,
Rusty Russell <rusty@rustcorp.com.au>,
"Michael S. Tsirkin" <mst@redhat.com>,
virtio-dev@lists.oasis-open.org,
virtualization@lists.linux-foundation.org,
Frank Swiderski <fes@google.com>
Subject: Re: [PATCH] virtio-blk: make the queue depth the max supportable by the hypervisor
Date: Sat, 15 Mar 2014 11:13:22 -0400 [thread overview]
Message-ID: <20140315151322.GA17270@thunk.org> (raw)
In-Reply-To: <20140315135723.GA10475@infradead.org>
On Sat, Mar 15, 2014 at 06:57:23AM -0700, Christoph Hellwig wrote:
> I don't think this should be a module parameter. The default sizing
> should be based of the parameters of the actual virtqueue, and if we
> want to allow tuning it it should be by a sysfs attribute, preferable
> using the same semantics as SCSI.
I wanted that too, but looking at the multiqueue code, it wasn't all
obvious how to safely adjust the queue depth once the virtio-blk
device driver is initialized and becomes active. There are all sorts
data structures including bitmaps, etc. that would have to be resized,
and I decided it would be too difficult / risky for me to make it be
dynamically resizeable.
So I settled on a module parameter thinking it would mostly only used
by testers / benchmarkers.
Can someone suggest a way to do a dynamic resizing of the virtio-blk
queue depth easily / safely?
- Ted
next prev parent reply other threads:[~2014-03-15 15:13 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1394841445-16142-1-git-send-email-venkateshs@google.com>
2014-03-15 3:34 ` [PATCH] virtio-blk: make the queue depth the max supportable by the hypervisor Theodore Ts'o
2014-03-15 10:57 ` Konrad Rzeszutek Wilk
2014-03-15 13:20 ` Theodore Ts'o
2014-03-15 13:57 ` Christoph Hellwig
2014-03-15 15:13 ` Theodore Ts'o [this message]
2014-03-17 0:42 ` Rusty Russell
2014-03-17 5:40 ` tytso
2014-03-19 6:28 ` Rusty Russell
2014-03-19 17:48 ` Venkatesh Srinivas
2014-03-25 18:50 ` Venkatesh Srinivas
2014-03-31 3:52 ` Rusty Russell
2014-04-01 2:27 ` Theodore Ts'o
2014-04-01 10:49 ` Stefan Hajnoczi
2014-04-02 7:36 ` Rusty Russell
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