From: Avi Kivity <avi@redhat.com>
To: Anthony Liguori <anthony@codemonkey.ws>
Cc: Gregory Haskins <ghaskins@novell.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
Chris Wright <chrisw@sous-sol.org>,
Gregory Haskins <gregory.haskins@gmail.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [RFC PATCH 0/3] generic hypercall support
Date: Fri, 08 May 2009 21:50:06 +0300 [thread overview]
Message-ID: <4A047EDE.2020806@redhat.com> (raw)
In-Reply-To: <4A044786.2080508@codemonkey.ws>
Anthony Liguori wrote:
>
> And we're now getting close to the point where the difference is
> virtually meaningless.
>
> At .14us, in order to see 1% CPU overhead added from PIO vs HC, you
> need 71429 exits.
>
If I read things correctly, you want the difference between PIO and
PIOoHC, which is 210ns. But your point stands, 50,000 exits/sec will
add 1% cpu overhead.
>
> The non-x86 architecture argument isn't valid because other
> architectures either 1) don't use PCI at all (s390) and are already
> using hypercalls 2) use PCI, but do not have a dedicated hypercall
> instruction (PPC emb) or 3) have PIO (ia64).
ia64 uses mmio to emulate pio, so the cost may be different. I agree on
x86 it's almost negligible.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2009-05-08 18:51 UTC|newest]
Thread overview: 115+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-05 13:24 [RFC PATCH 0/3] generic hypercall support Gregory Haskins
2009-05-05 13:24 ` [RFC PATCH 1/3] add " Gregory Haskins
2009-05-05 17:03 ` Hollis Blanchard
2009-05-06 13:52 ` Anthony Liguori
2009-05-06 15:16 ` Gregory Haskins
2009-05-06 16:52 ` Arnd Bergmann
2009-05-05 13:24 ` [RFC PATCH 2/3] x86: " Gregory Haskins
2009-05-05 13:24 ` [RFC PATCH 3/3] kvm: add pv_cpu_ops.hypercall support to the guest Gregory Haskins
2009-05-05 13:36 ` [RFC PATCH 0/3] generic hypercall support Avi Kivity
2009-05-05 13:40 ` Gregory Haskins
2009-05-05 14:00 ` Avi Kivity
2009-05-05 14:14 ` Gregory Haskins
2009-05-05 14:21 ` Gregory Haskins
2009-05-05 15:02 ` Avi Kivity
2009-05-05 23:17 ` Chris Wright
2009-05-06 3:51 ` Gregory Haskins
2009-05-06 7:22 ` Chris Wright
2009-05-06 13:17 ` Gregory Haskins
2009-05-06 16:07 ` Chris Wright
2009-05-07 17:03 ` Gregory Haskins
2009-05-07 18:05 ` Avi Kivity
2009-05-07 18:08 ` Gregory Haskins
2009-05-07 18:12 ` Avi Kivity
2009-05-07 18:16 ` Gregory Haskins
2009-05-07 18:24 ` Avi Kivity
2009-05-07 18:37 ` Gregory Haskins
2009-05-07 19:00 ` Avi Kivity
2009-05-07 19:05 ` Gregory Haskins
2009-05-07 19:43 ` Avi Kivity
2009-05-07 20:07 ` Gregory Haskins
2009-05-07 20:15 ` Avi Kivity
2009-05-07 20:26 ` Gregory Haskins
2009-05-08 8:35 ` Avi Kivity
2009-05-08 11:29 ` Gregory Haskins
2009-05-07 19:07 ` Chris Wright
2009-05-07 19:12 ` Gregory Haskins
2009-05-07 19:21 ` Chris Wright
2009-05-07 19:26 ` Avi Kivity
2009-05-07 19:44 ` Avi Kivity
2009-05-07 19:29 ` Gregory Haskins
2009-05-07 20:25 ` Chris Wright
2009-05-07 20:34 ` Gregory Haskins
2009-05-07 20:54 ` Arnd Bergmann
2009-05-07 21:13 ` Gregory Haskins
2009-05-07 21:57 ` Chris Wright
2009-05-07 22:11 ` Arnd Bergmann
2009-05-08 22:33 ` Benjamin Herrenschmidt
2009-05-11 13:01 ` Arnd Bergmann
2009-05-11 13:04 ` Gregory Haskins
2009-05-07 20:00 ` Arnd Bergmann
2009-05-07 20:31 ` Gregory Haskins
2009-05-07 20:42 ` Arnd Bergmann
2009-05-07 20:47 ` Arnd Bergmann
2009-05-07 20:50 ` Chris Wright
2009-05-07 23:35 ` Marcelo Tosatti
2009-05-07 23:43 ` Marcelo Tosatti
2009-05-08 3:17 ` Gregory Haskins
2009-05-08 7:55 ` Avi Kivity
[not found] ` <20090508103253.GC3011@amt.cnet>
2009-05-08 11:37 ` Avi Kivity
2009-05-08 14:35 ` Marcelo Tosatti
2009-05-08 14:45 ` Gregory Haskins
2009-05-08 15:51 ` Marcelo Tosatti
2009-05-08 19:56 ` David S. Ahern
2009-05-08 20:01 ` Gregory Haskins
2009-05-08 23:23 ` David S. Ahern
2009-05-09 8:45 ` Avi Kivity
2009-05-09 11:27 ` Gregory Haskins
2009-05-10 4:27 ` David S. Ahern
2009-05-10 5:24 ` Avi Kivity
2009-05-10 4:24 ` David S. Ahern
2009-05-08 3:13 ` Gregory Haskins
2009-05-08 7:59 ` Avi Kivity
2009-05-08 11:09 ` Gregory Haskins
[not found] ` <20090508104228.GD3011@amt.cnet>
2009-05-08 12:43 ` Gregory Haskins
2009-05-08 15:33 ` Marcelo Tosatti
2009-05-08 19:02 ` Avi Kivity
2009-05-08 16:48 ` Paul E. McKenney
2009-05-08 19:55 ` Gregory Haskins
2009-05-08 14:15 ` Gregory Haskins
2009-05-08 14:53 ` Anthony Liguori
2009-05-08 18:50 ` Avi Kivity [this message]
2009-05-08 19:02 ` Anthony Liguori
2009-05-08 19:06 ` Avi Kivity
2009-05-11 16:37 ` Jeremy Fitzhardinge
2009-05-07 12:29 ` Avi Kivity
2009-05-08 14:59 ` Anthony Liguori
2009-05-09 12:01 ` Gregory Haskins
2009-05-10 18:38 ` Anthony Liguori
2009-05-11 13:14 ` Gregory Haskins
2009-05-11 16:35 ` Hollis Blanchard
2009-05-11 17:06 ` Avi Kivity
2009-05-11 17:29 ` Gregory Haskins
2009-05-11 17:53 ` Avi Kivity
2009-05-11 17:51 ` Anthony Liguori
2009-05-11 18:02 ` Avi Kivity
2009-05-11 18:18 ` Anthony Liguori
2009-05-11 17:31 ` Anthony Liguori
2009-05-13 10:53 ` Gregory Haskins
2009-05-13 14:45 ` Gregory Haskins
2009-05-11 16:44 ` Hollis Blanchard
2009-05-11 17:54 ` Anthony Liguori
2009-05-11 19:24 ` PowerPC page faults Hollis Blanchard
2009-05-11 22:17 ` Anthony Liguori
2009-05-12 5:46 ` Liu Yu-B13201
2009-05-12 14:50 ` Hollis Blanchard
2009-05-06 13:56 ` [RFC PATCH 0/3] generic hypercall support Anthony Liguori
2009-05-06 16:03 ` Gregory Haskins
2009-05-08 8:17 ` Avi Kivity
2009-05-08 15:20 ` Gregory Haskins
2009-05-08 17:00 ` Avi Kivity
2009-05-08 18:55 ` Gregory Haskins
2009-05-08 19:05 ` Anthony Liguori
2009-05-08 19:12 ` Avi Kivity
2009-05-08 19:59 ` Gregory Haskins
2009-05-10 9:59 ` Avi Kivity
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