From: Avi Kivity <avi@redhat.com>
To: Gleb Natapov <gleb@redhat.com>
Cc: Daniel Gollub <gollub@b1-systems.de>,
"Daniel P. Berrange" <berrange@redhat.com>,
kvm@vger.kernel.org, qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [PATCH 0/2] Introduce panic hypercall
Date: Tue, 21 Jun 2011 12:07:26 +0300 [thread overview]
Message-ID: <4E005F4E.1060200@redhat.com> (raw)
In-Reply-To: <20110621090348.GE491@redhat.com>
On 06/21/2011 12:03 PM, Gleb Natapov wrote:> >>
> > >Something like steal time, but for watchdog. But this become complicated fast.
> > >Watchdog emulation will have to move into kernel for starter.
> >
> > Why? You can use a performance counter from userspace.
> >
> Heh, haven't thought about such way of implementing watchdog device.
> But the same question again: what impact on performance constantly running
> guest under perf is?
Same answer.
> Doesn't running guest under perf involve a lot of
> NMIs (and hence vmexists)?
The NMI rate is proportional to how you program the counter. If you
program it to exit every 2 billion cycles, that's what you'll get.
--
error compiling committee.c: too many arguments to function
WARNING: multiple messages have this Message-ID (diff)
From: Avi Kivity <avi@redhat.com>
To: Gleb Natapov <gleb@redhat.com>
Cc: Daniel Gollub <gollub@b1-systems.de>,
qemu-devel <qemu-devel@nongnu.org>,
kvm@vger.kernel.org
Subject: Re: [Qemu-devel] [PATCH 0/2] Introduce panic hypercall
Date: Tue, 21 Jun 2011 12:07:26 +0300 [thread overview]
Message-ID: <4E005F4E.1060200@redhat.com> (raw)
In-Reply-To: <20110621090348.GE491@redhat.com>
On 06/21/2011 12:03 PM, Gleb Natapov wrote:> >>
> > >Something like steal time, but for watchdog. But this become complicated fast.
> > >Watchdog emulation will have to move into kernel for starter.
> >
> > Why? You can use a performance counter from userspace.
> >
> Heh, haven't thought about such way of implementing watchdog device.
> But the same question again: what impact on performance constantly running
> guest under perf is?
Same answer.
> Doesn't running guest under perf involve a lot of
> NMIs (and hence vmexists)?
The NMI rate is proportional to how you program the counter. If you
program it to exit every 2 billion cycles, that's what you'll get.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-06-21 9:07 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-20 13:38 [PATCH 0/2] Introduce panic hypercall Daniel Gollub
2011-06-20 13:38 ` [PATCH 1/2] Inroduce panic hypercall KVM_HC_PANIC (host) Daniel Gollub
2011-06-20 13:38 ` [PATCH 2/2] Call KVM_HC_PANIC if guest panics Daniel Gollub
2011-06-20 15:31 ` [PATCH 0/2] Introduce panic hypercall Avi Kivity
2011-06-20 15:38 ` Daniel P. Berrange
2011-06-20 15:45 ` Avi Kivity
2011-06-20 15:45 ` [Qemu-devel] " Avi Kivity
2011-06-20 15:59 ` Jan Kiszka
2011-06-20 15:59 ` [Qemu-devel] " Jan Kiszka
2011-06-20 16:26 ` Daniel Gollub
2011-06-20 16:26 ` [Qemu-devel] " Daniel Gollub
2011-06-20 16:34 ` Avi Kivity
2011-06-20 16:34 ` [Qemu-devel] " Avi Kivity
2011-06-20 17:13 ` Jan Kiszka
2011-06-20 17:13 ` [Qemu-devel] " Jan Kiszka
2011-06-20 17:23 ` Avi Kivity
2011-06-20 17:23 ` [Qemu-devel] " Avi Kivity
2011-06-21 6:04 ` Gleb Natapov
2011-06-21 6:04 ` [Qemu-devel] " Gleb Natapov
2011-06-21 6:02 ` Gleb Natapov
2011-06-21 6:02 ` [Qemu-devel] " Gleb Natapov
2011-06-21 8:09 ` Avi Kivity
2011-06-21 8:09 ` [Qemu-devel] " Avi Kivity
2011-06-21 8:41 ` Gleb Natapov
2011-06-21 8:41 ` [Qemu-devel] " Gleb Natapov
2011-06-21 8:56 ` Avi Kivity
2011-06-21 8:56 ` [Qemu-devel] " Avi Kivity
2011-06-21 9:03 ` Gleb Natapov
2011-06-21 9:03 ` [Qemu-devel] " Gleb Natapov
2011-06-21 9:07 ` Avi Kivity [this message]
2011-06-21 9:07 ` Avi Kivity
2011-06-21 9:30 ` shawn che
2011-06-21 9:30 ` [Qemu-devel] " shawn che
2011-06-20 19:28 ` Anthony Liguori
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