From: Paul Mackerras <paulus@samba.org>
To: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
mingo@elte.hu, efault@gmx.de, avi@redhat.com, acme@redhat.com,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCHSET] sched,perf: unify tracers in sched and move perf on top of TP
Date: Mon, 10 May 2010 15:20:56 +1000 [thread overview]
Message-ID: <20100510052056.GB20793@drongo> (raw)
In-Reply-To: <4BE1406C.2000400@kernel.org>
On Wed, May 05, 2010 at 11:54:52AM +0200, Tejun Heo wrote:
> On 05/05/2010 11:51 AM, Peter Zijlstra wrote:
> >> I was wondering the other way around - ie. the possibility to make
> >> perf optional and maybe even as a module which depends on TPs, which
> >> would be nicer than the current situation and make the code less
> >> cluttered too.
> >
> > I really really hate making perf rely on tracepoints.
>
> Hmmm.... may I ask why? Unifying hooking mechanism seems like a good
> idea to me and it's not like it's gonna add any runtime overhead
> although it does complicate init/exit but well that's something you
> have to pay if you wanna do things dynamically and sans the ifdef
> stuff it's like a couple hundred lines of isolated code.
Don't forget where perf_events started out - as a way to count and
record hardware events. So perf_events is very useful even in a
kernel that has no tracing infrastructure configured in at all.
Paul.
next prev parent reply other threads:[~2010-05-10 5:22 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-04 12:38 [RFC PATCHSET] sched,perf: unify tracers in sched and move perf on top of TP Tejun Heo
2010-05-04 12:38 ` [PATCH 01/12] sched: drop @cpu argument from sched_in preempt notifier Tejun Heo
2010-05-04 17:11 ` Peter Zijlstra
2010-05-04 12:38 ` [PATCH 02/12] sched: rename preempt_notifiers to sched_notifiers and refactor implementation Tejun Heo
2010-05-04 12:38 ` [PATCH 03/12] perf: add perf_event_task_migrate() Tejun Heo
2010-05-05 5:08 ` Frederic Weisbecker
2010-05-05 5:16 ` Tejun Heo
2010-05-05 9:11 ` Peter Zijlstra
2010-05-05 9:37 ` Tejun Heo
2010-05-05 9:50 ` Peter Zijlstra
2010-05-05 9:56 ` Tejun Heo
2010-05-04 12:38 ` [PATCH 04/12] perf: add @rq to perf_event_task_sched_out() Tejun Heo
2010-05-04 17:11 ` Peter Zijlstra
2010-05-04 17:22 ` Tejun Heo
2010-05-04 17:42 ` Peter Zijlstra
2010-05-04 18:22 ` Steven Rostedt
2010-05-04 18:26 ` Peter Zijlstra
2010-05-04 18:32 ` Steven Rostedt
2010-05-05 4:48 ` Tejun Heo
2010-05-05 9:58 ` Tejun Heo
2010-05-07 18:41 ` [tip:sched/core] sched: Remove rq argument to the tracepoints tip-bot for Peter Zijlstra
2010-05-04 12:38 ` [PATCH 05/12] perf: move perf_event_task_sched_in() next to fire_sched_notifiers_in() Tejun Heo
2010-05-04 12:38 ` [PATCH 06/12] sched: relocate fire_sched_notifiers_out() and trace_sched_switch() Tejun Heo
2010-05-04 12:38 ` [PATCH 07/12] sched: coalesce event notifiers Tejun Heo
2010-05-04 12:38 ` [PATCH 08/12] sched: add switch_in and tick tracepoints Tejun Heo
2010-05-04 12:38 ` [PATCH 09/12] perf: factor out perf_event_switch_clones() Tejun Heo
2010-05-04 12:38 ` [PATCH 10/12] perf: make nr_events an int and add perf_online_mutex to protect it Tejun Heo
2010-05-04 12:38 ` [PATCH 11/12] perf: prepare to move sched perf functions on top of tracepoints Tejun Heo
2010-05-04 12:38 ` [PATCH 12/12] perf: " Tejun Heo
2010-05-04 17:29 ` [RFC PATCHSET] sched,perf: unify tracers in sched and move perf on top of TP Peter Zijlstra
2010-05-05 5:00 ` Tejun Heo
2010-05-05 9:06 ` Peter Zijlstra
2010-05-05 9:32 ` Tejun Heo
2010-05-05 9:51 ` Peter Zijlstra
2010-05-05 9:54 ` Tejun Heo
2010-05-05 11:38 ` Peter Zijlstra
2010-05-05 12:28 ` Tejun Heo
2010-05-05 16:55 ` Ingo Molnar
2010-05-05 18:12 ` Peter Zijlstra
2010-05-05 18:16 ` Peter Zijlstra
2010-05-05 18:30 ` Frederic Weisbecker
2010-05-06 6:28 ` Ingo Molnar
2010-05-06 7:11 ` Tejun Heo
2010-05-06 8:27 ` Ingo Molnar
2010-05-06 8:41 ` Tejun Heo
2010-05-06 8:18 ` Avi Kivity
2010-05-06 6:31 ` Ingo Molnar
2010-05-06 7:04 ` Peter Zijlstra
2010-05-06 7:11 ` Ingo Molnar
2010-05-06 7:29 ` Tejun Heo
2010-05-06 7:33 ` Tejun Heo
2010-05-05 12:33 ` Avi Kivity
2010-05-05 13:09 ` Tejun Heo
2010-05-10 5:20 ` Paul Mackerras [this message]
2010-05-10 5:48 ` Tejun Heo
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=20100510052056.GB20793@drongo \
--to=paulus@samba.org \
--cc=acme@redhat.com \
--cc=avi@redhat.com \
--cc=efault@gmx.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=peterz@infradead.org \
--cc=tj@kernel.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