From: Kevin Wolf <kwolf@redhat.com>
To: Fam Zheng <famz@redhat.com>
Cc: pbonzini@redhat.com, berto@igalia.com, qemu-devel@nongnu.org,
Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] block/throttle: Use host clock type
Date: Mon, 16 Mar 2015 17:08:52 +0100 [thread overview]
Message-ID: <20150316160852.GG4707@noname.redhat.com> (raw)
In-Reply-To: <1426228529-15969-1-git-send-email-famz@redhat.com>
Am 13.03.2015 um 07:35 hat Fam Zheng geschrieben:
> Throttle timers won't make any progress when VCPU is not running, which
> is prone to stall the request queue in cases like utils, qtest,
> suspending, and live migration, unless carefully handled. What we do now
> is crude. For example in bdrv_drain_all, requests are resumed
> immediately without consulting throttling timer. Unfortunately
> bdrv_drain_all is so widely used that there may be too many holes that
> guest could bypass throttling.
>
> If we use the host clock, we can just trust the nested poll when waiting
> for requests.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
This breaks qemu-iotests 093. Dropped it again from the block branch.
Kevin
prev parent reply other threads:[~2015-03-16 16:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-13 6:35 [Qemu-devel] [PATCH] block/throttle: Use host clock type Fam Zheng
2015-03-13 8:08 ` Paolo Bonzini
2015-03-13 8:27 ` Fam Zheng
2015-03-13 11:09 ` Paolo Bonzini
2015-03-13 11:43 ` Fam Zheng
2015-03-13 12:23 ` Alberto Garcia
2015-03-13 12:28 ` Paolo Bonzini
2015-03-16 2:15 ` Fam Zheng
2015-03-16 15:18 ` Kevin Wolf
2015-03-16 16:08 ` Kevin Wolf [this message]
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