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From: Fam Zheng <famz@redhat.com>
To: Chris Friesen <chris.friesen@windriver.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] block IO thread creation question
Date: Fri, 25 Mar 2016 10:25:47 +0800	[thread overview]
Message-ID: <20160325022547.GE29171@ad.usersys.redhat.com> (raw)
In-Reply-To: <56F4017D.7040502@windriver.com>

On Thu, 03/24 09:02, Chris Friesen wrote:
> Hi,
> 
> Could someone point me at the code for creating threads to handle
> block IO?  I'm seeing up to 30 threads per virtual disk, which seems
> high.

It is thread-pool.c, assuming you are using "aio=threads" for drive, which is
the default. With the alternative, "aio=native", spawning worker threads will
be much more uncommon.

Fam

> 
> In case it's related, the block devices are iSCSI with the host
> acting as the initiator and exposing block devices to qemu.
> 
> I'm particularly interested in qemu 2.2, just in case things have
> changed significantly since then.
> 
> Thanks,
> Chris
> 

      reply	other threads:[~2016-03-25  2:25 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-24 15:02 [Qemu-devel] block IO thread creation question Chris Friesen
2016-03-25  2:25 ` Fam Zheng [this message]

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