From: Frederic Weisbecker <fweisbec@gmail.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: linux-kernel@vger.kernel.org, linux-hotplug@vger.kernel.org,
rostedt@goodmis.org, amit.kucheria@linaro.org
Subject: Re: [PATCH V2] tracing, perf : add cpu hotplug trace events
Date: Fri, 21 Jan 2011 17:44:07 +0100 [thread overview]
Message-ID: <20110121164404.GA2520@nowhere> (raw)
In-Reply-To: <AANLkTinhX6UwQA0HFhuu5=jbq84woVhqtahuzA5hEo2o@mail.gmail.com>
On Fri, Jan 21, 2011 at 09:43:18AM +0100, Vincent Guittot wrote:
> On 20 January 2011 17:11, Frederic Weisbecker <fweisbec@gmail.com> wrote:
> > On Thu, Jan 20, 2011 at 09:25:54AM +0100, Vincent Guittot wrote:
> >> Please find below a new proposal for adding trace events for cpu hotplug.
> >> The goal is to measure the latency of each part (kernel, architecture)
> >> and also to trace the cpu hotplug activity with other power events. I
> >> have tested these traces events on an arm platform.
> >>
> >> Changes since previous version:
> >> -Use cpu_hotplug for trace name
> >> -Define traces for kernel core and arch parts only
> >> -Use DECLARE_EVENT_CLASS and DEFINE_EVENT
> >> -Use proper indentation
> >>
> >> Subject: [PATCH] cpu hotplug tracepoint
> >>
> >> this patch adds new events for cpu hotplug tracing
> >> * plug/unplug sequence
> >> * core and architecture latency measurements
> >>
> >> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.com>
> >> ---
> >> include/trace/events/cpu_hotplug.h | 117 ++++++++++++++++++++++++++++++++++++
> >
> > Note we can't apply new tracepoints if they are not inserted in the code.
>
> I agree, i just want to have 1st feedbacks on the tracepoint interface
> before providing a patch which inserts the trace in the code.
>
> >
> >> +DEFINE_EVENT(cpu_hotplug, cpu_hotplug_arch_wait_die_start,
> >> +
> >> + TP_PROTO(unsigned int cpuid),
> >> +
> >> + TP_ARGS(cpuid)
> >> +);
> >> +
> >> +DEFINE_EVENT(cpu_hotplug, cpu_hotplug_arch_wait_die_end,
> >> +
> >> + TP_PROTO(unsigned int cpuid),
> >> +
> >> + TP_ARGS(cpuid)
> >> +);
> >
> > What is wait die, compared to die for example?
> >
>
> The arch_wait_die is used to trace the process which waits for the cpu
> to die (__cpu_die) and the arch_die is used to trace when the cpu dies
> (cpu_die)
I still can't find the difference.
Having:
trace_cpu_hotplug_arch_die_start(cpu)
__cpu_die();
trace_cpu_hotplug_arch_die_end(cpu)
Is not enough to get both the information that a cpu dies
and the time took to do so?
next prev parent reply other threads:[~2011-01-21 16:44 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-20 8:25 [PATCH V2] tracing, perf : add cpu hotplug trace events Vincent Guittot
2011-01-20 16:11 ` Frederic Weisbecker
2011-01-21 8:43 ` Vincent Guittot
2011-01-21 16:44 ` Frederic Weisbecker [this message]
2011-01-21 17:41 ` Vincent Guittot
2011-01-22 2:42 ` Frederic Weisbecker
2011-01-24 9:02 ` Vincent Guittot
2011-01-21 17:28 ` Steven Rostedt
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=20110121164404.GA2520@nowhere \
--to=fweisbec@gmail.com \
--cc=amit.kucheria@linaro.org \
--cc=linux-hotplug@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=vincent.guittot@linaro.org \
/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).