From: Marcelo Tosatti <mtosatti@redhat.com>
To: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Avi Kivity <avi@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH 2/3] KVM: improve trace events of vmexit/mmio/ioport
Date: Tue, 17 Jan 2012 09:55:58 -0200 [thread overview]
Message-ID: <20120117115558.GB17420@amt.cnet> (raw)
In-Reply-To: <4F14DCBB.3060207@linux.vnet.ibm.com>
On Tue, Jan 17, 2012 at 10:28:11AM +0800, Xiao Guangrong wrote:
> On 01/16/2012 05:38 PM, Avi Kivity wrote:
>
> > On 01/16/2012 11:32 AM, Xiao Guangrong wrote:
> >> - trace vcpu_id for these events
> >
> > We can infer the vcpu id from the kvm_entry tracepoints, no?
> >
>
>
> Thanks for your review, Avi!
>
> Hmm. i think it is hard to do since the vcpu thread can be scheduled
> anytime, one example is as follow:
>
> CPU 0
>
> kvm_entry vcpu 0
> ......
> kvm_entry vcpu 1
> ......
> event1 occurs
> ......
> event2 occurs
>
> It is hard to know the event belong to which kvm_entry?
>
> >> - add kvm_mmio_done to trace the time when mmio/ioport emulation is completed
> >
> > ditto?
> >
>
>
> I think is ok to get the event end time by using kvm_entry.
>
> >
> > Relying on the existing tracepoints will make the tool work on older
> > kernels.
> >
>
>
> We can drop all new events, but unfortunately, the information of the origin
> tracepoints is not enough, at least vcpu_id need be traced in theses events
> to match its events. Yes?
Yes, and if you don't add completed events, you'll have to use kvm_entry
whose collection adds a lot of overhead.
next prev parent reply other threads:[~2012-01-17 12:00 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-16 9:30 [RFC][PATCH] KVM: perf: a smart tool to analyse kvm events Xiao Guangrong
2012-01-16 9:31 ` [PATCH 1/3] KVM: trace mmio read event properly Xiao Guangrong
2012-01-16 10:18 ` Avi Kivity
2012-01-17 2:36 ` Xiao Guangrong
2012-01-16 9:32 ` [PATCH 2/3] KVM: improve trace events of vmexit/mmio/ioport Xiao Guangrong
2012-01-16 9:38 ` Avi Kivity
2012-01-17 2:28 ` Xiao Guangrong
2012-01-17 11:55 ` Marcelo Tosatti [this message]
2012-01-17 17:31 ` David Ahern
2012-01-18 2:32 ` Xiao Guangrong
2012-01-18 5:34 ` David Ahern
2012-01-24 12:44 ` Avi Kivity
2012-01-16 9:32 ` [PATCH 3/3] KVM: perf: kvm events analysis tool Xiao Guangrong
2012-01-16 10:04 ` Avi Kivity
2012-01-17 2:30 ` Xiao Guangrong
2012-01-24 12:49 ` Avi Kivity
2012-01-16 10:08 ` Stefan Hajnoczi
2012-01-17 2:37 ` Xiao Guangrong
2012-01-17 11:59 ` Marcelo Tosatti
2012-01-24 12:51 ` Avi Kivity
2012-01-16 10:11 ` [RFC][PATCH] KVM: perf: a smart tool to analyse kvm events Avi Kivity
2012-01-17 2:30 ` Xiao Guangrong
2012-01-16 22:53 ` David Ahern
2012-01-17 2:41 ` Xiao Guangrong
2012-01-17 4:49 ` David Ahern
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=20120117115558.GB17420@amt.cnet \
--to=mtosatti@redhat.com \
--cc=avi@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=xiaoguangrong@linux.vnet.ibm.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).