From: Paolo Bonzini <pbonzini@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: "Andreas Färber" <afaerber@suse.de>,
"Alex Bennée" <alex.bennee@linaro.org>,
"QEMU Developers" <qemu-devel@nongnu.org>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
mohamad.gebai@gmail.com
Subject: Re: [Qemu-devel] [PATCH v2 3/3] trace: instrument and trace tcg tb flush activity
Date: Tue, 15 Jul 2014 22:38:32 +0200 [thread overview]
Message-ID: <53C59148.3020501@redhat.com> (raw)
In-Reply-To: <CAFEAcA8fKaDQbAu4CrprETqaSwEpSmsxanhOfpTwL8hk+ku0rw@mail.gmail.com>
Il 15/07/2014 22:29, Peter Maydell ha scritto:
>> >
>> > I think it's not a big deal if you always enable the counting, and perhaps
>> > show them in "info jit".
> We don't enable any other tracepoints by default; why would
> we want to enable just this one which is in a hot codepath??
I'm not referring to the tracepoint, only to trace_inc_counter instead
of just "x++". The overhead is probably not measurable. There are a few
low-hanging fruit optimizations in cpu-exec.c that probably would give
more measurable benefit, for example trying to replace cpu_loop_exit
with a goto whenever possible.
Paolo
prev parent reply other threads:[~2014-07-15 20:38 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-15 11:42 [Qemu-devel] [PATCH v2 0/3] some TCG related trace patches Alex Bennée
2014-07-15 11:42 ` [Qemu-devel] [PATCH v2 1/3] trace: teach lttng backend to use format strings Alex Bennée
2014-08-01 9:05 ` Alex Bennée
2014-08-01 12:54 ` Stefan Hajnoczi
2014-07-15 11:42 ` [Qemu-devel] [PATCH v2 2/3] trace: add some tcg tracing support Alex Bennée
2014-07-15 11:42 ` [Qemu-devel] [PATCH v2 3/3] trace: instrument and trace tcg tb flush activity Alex Bennée
2014-07-15 12:15 ` Andreas Färber
2014-07-15 13:12 ` Alex Bennée
2014-07-15 12:23 ` Peter Maydell
2014-07-15 13:07 ` Peter Maydell
2014-07-15 13:10 ` Alex Bennée
2014-07-15 13:19 ` Paolo Bonzini
2014-07-15 14:16 ` Alex Bennée
2014-07-15 20:11 ` Paolo Bonzini
2014-07-15 20:29 ` Peter Maydell
2014-07-15 20:38 ` Paolo Bonzini [this message]
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=53C59148.3020501@redhat.com \
--to=pbonzini@redhat.com \
--cc=afaerber@suse.de \
--cc=alex.bennee@linaro.org \
--cc=mohamad.gebai@gmail.com \
--cc=peter.maydell@linaro.org \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@redhat.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).