From: Paolo Bonzini <pbonzini@redhat.com>
To: Zhi Yong Wu <zwu.kernel@gmail.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>,
qemu-devel@nongnu.org, stefanha@linux.vnet.ibm.com
Subject: Re: [Qemu-devel] [PATCH] block: add the support to drain throttled requests
Date: Tue, 20 Mar 2012 10:47:28 +0100 [thread overview]
Message-ID: <4F685230.9040209@redhat.com> (raw)
In-Reply-To: <CAEH94LhwKWyg8pVTY7-SeB68eBRY-1-tDQ=Z=pXtH2_amr4jFw@mail.gmail.com>
Il 20/03/2012 10:40, Zhi Yong Wu ha scritto:
> HI, Kevin,
>
> We hope that I/O throttling can be shipped without known issue in QEMU
> 1.1, so if you are available, can you give this patch some love?
I'm sorry to say this, but I think I/O throttling is impossible to save.
As it is implemented now, it just cannot work in the presence of
synchronous I/O, except at the cost of busy waiting with the global
mutex taken. See the message from Stefan yesterday.
Unfortunately I don't have any solution for this, except perhaps
disabling throttling around synchronous I/O.
Paolo
next prev parent reply other threads:[~2012-03-20 9:48 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-13 1:53 [Qemu-devel] [PATCH] block: add the support to drain throttled requests zwu.kernel
2012-03-20 9:40 ` Zhi Yong Wu
2012-03-20 9:47 ` Paolo Bonzini [this message]
2012-03-20 9:58 ` Kevin Wolf
2012-03-20 11:44 ` Stefan Hajnoczi
2012-03-22 19:07 ` Chris Webb
2012-03-23 10:38 ` Stefan Hajnoczi
2012-03-23 10:43 ` Chris Webb
2012-03-23 10:50 ` Stefan Hajnoczi
2012-03-23 11:02 ` Richard Davies
2012-03-23 11:32 ` Stefan Hajnoczi
2012-03-23 16:56 ` Stefan Hajnoczi
2012-03-26 14:21 ` Stefan Hajnoczi
2012-03-26 14:31 ` Kevin Wolf
2012-03-27 4:29 ` Zhi Yong Wu
2012-03-27 6:52 ` Stefan Hajnoczi
2012-03-20 9:56 ` Kevin Wolf
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