All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Zhang, Xiantao" <xiantao.zhang@intel.com>
To: Avi Kivity <avi@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Gleb Natapov <gleb@redhat.com>,
	Peter Zijlstra <peter@programming.kicks-ass.net>
Subject: RE: x86: use smp_send_reschedule in kvm_vcpu_kick
Date: Thu, 12 Mar 2009 10:31:47 +0800	[thread overview]
Message-ID: <706158FABBBA044BAD4FE898A02E4BC224451E95@pdsmsx503.ccr.corp.intel.com> (raw)
In-Reply-To: <49B61E65.4070706@redhat.com>

Avi Kivity wrote:
> Marcelo Tosatti wrote:
>> OK, reworked patch:
>> - change ia64 in addition to x86
>> - add comment on smp send reschedule handlers about KVM's usage
>> 
>> Untested on IA64.
>> 
>> KVM: use smp_send_reschedule in kvm_vcpu_kick
>> 
>> KVM uses a function call IPI to cause the exit of a guest running on
>> a physical cpu. For virtual interrupt notification there is no need
>> to wait on IPI receival, or to execute any function.
>> 
>> This is exactly what the reschedule IPI does, without the overhead
>> of function IPI. So use it instead of smp_call_function_single in
>> kvm_vcpu_kick. 
>> 
>> Also change the "guest_mode" variable to a bit in vcpu->requests, and
>> use that to collapse multiple IPI's that would be issued between the
>> first one and zeroing of guest mode.
>> 
>> This allows kvm_vcpu_kick to called with interrupts disabled.
>> 
> 
> Looks good. Will wait for Xiantao's test-n-ack before applying.

kvm-ia64 is broken due to recent check-ins about irq-bits, and we are trying to fix it. For this patch, ia64 has to export the symbol smp_send_reschedule before applying the patch.
Xiantao

  reply	other threads:[~2009-03-12  2:33 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-03  0:14 KVM: " Marcelo Tosatti
2009-03-03  7:53 ` Zhang, Xiantao
2009-03-03 13:25   ` Marcelo Tosatti
2009-03-03 13:25     ` Gleb Natapov
2009-03-03 13:56       ` Marcelo Tosatti
2009-03-09 10:17 ` KVM: " Avi Kivity
2009-03-09 10:58   ` Ingo Molnar
2009-03-09 11:09     ` Peter Zijlstra
2009-03-09 23:23       ` Marcelo Tosatti
2009-03-10  8:01         ` Avi Kivity
2009-03-12  2:31           ` Zhang, Xiantao [this message]
2009-03-12  7:06             ` Avi Kivity
2009-03-12 11:04             ` Gleb Natapov
2009-03-13  2:15               ` Zhang, Xiantao
2009-03-19  7:38                 ` Gleb Natapov
2009-03-19  7:56                   ` Zhang, Xiantao
2009-03-19  8:11                     ` Gleb Natapov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=706158FABBBA044BAD4FE898A02E4BC224451E95@pdsmsx503.ccr.corp.intel.com \
    --to=xiantao.zhang@intel.com \
    --cc=avi@redhat.com \
    --cc=gleb@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=mtosatti@redhat.com \
    --cc=peter@programming.kicks-ass.net \
    --subject='RE: x86: use smp_send_reschedule in kvm_vcpu_kick' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.