From: Andi Kleen <andi@firstfloor.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <andi@firstfloor.org>,
"Liang, Kan" <kan.liang@intel.com>, Jiri Olsa <jolsa@redhat.com>,
"mingo@redhat.com" <mingo@redhat.com>,
"acme@kernel.org" <acme@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"alexander.shishkin@linux.intel.com"
<alexander.shishkin@linux.intel.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"namhyung@kernel.org" <namhyung@kernel.org>,
"jolsa@kernel.org" <jolsa@kernel.org>,
"Hunter, Adrian" <adrian.hunter@intel.com>,
"wangnan0@huawei.com" <wangnan0@huawei.com>,
"mark.rutland@arm.com" <mark.rutland@arm.com>
Subject: Re: [PATCH 01/14] perf/x86: Introduce PERF_RECORD_OVERHEAD
Date: Thu, 24 Nov 2016 11:02:16 -0800 [thread overview]
Message-ID: <20161124190216.GE26852@two.firstfloor.org> (raw)
In-Reply-To: <20161124185849.GJ3092@twins.programming.kicks-ass.net>
On Thu, Nov 24, 2016 at 07:58:49PM +0100, Peter Zijlstra wrote:
> On Thu, Nov 24, 2016 at 10:28:22AM -0800, Andi Kleen wrote:
> > On Thu, Nov 24, 2016 at 02:50:43PM +0100, Peter Zijlstra wrote:
> > > On Thu, Nov 24, 2016 at 01:45:28PM +0000, Liang, Kan wrote:
> > > > > I think we should make this optional/configurable like the rest of the aux
> > > > > events, like below..
> > > > >
> > > >
> > > > The overhead logging only happens when event is going to be disabled or
> > > > the task is scheduling out. It should not be much and expensive.
> > > >
> > > > Peter,
> > > >
> > > > What do you think?
> > > > Should we make it configurable?
> > >
> > > Is there a downside to having it optional?
> >
> > It would be good to always have at least one line overhead summary in the
> > default output. So if someone sends you a perf report output file and it has
> > suspicious overhead can investigate.
>
> Sure, but that's a tool thing, totally irrelevant for the kernel.
It requires enabling the overhead records by default.
If there is really concern about not supporting old tool would need a
disable instead of an enable option.
-Andi
next prev parent reply other threads:[~2016-11-24 19:02 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-23 9:44 [PATCH 00/14] export perf overheads information kan.liang
2016-11-23 9:44 ` [PATCH 01/14] perf/x86: Introduce PERF_RECORD_OVERHEAD kan.liang
2016-11-23 20:11 ` Peter Zijlstra
2016-11-23 20:13 ` Peter Zijlstra
2016-11-23 23:41 ` Jiri Olsa
2016-11-24 13:45 ` Liang, Kan
2016-11-24 13:50 ` Peter Zijlstra
2016-11-24 13:56 ` Liang, Kan
2016-11-24 14:27 ` Jiri Olsa
2016-11-24 14:39 ` Liang, Kan
2016-11-24 14:47 ` Jiri Olsa
2016-11-24 18:28 ` Andi Kleen
2016-11-24 18:58 ` Peter Zijlstra
2016-11-24 19:02 ` Andi Kleen [this message]
2016-11-24 19:08 ` Peter Zijlstra
2016-11-23 9:44 ` [PATCH 02/14] perf/x86: output NMI overhead kan.liang
2016-11-23 20:06 ` Peter Zijlstra
2016-11-24 16:19 ` Mark Rutland
2016-11-24 19:02 ` Peter Zijlstra
2016-11-24 19:40 ` Liang, Kan
2016-11-24 23:26 ` Namhyung Kim
2016-11-23 9:44 ` [PATCH 03/14] perf/x86: output multiplexing overhead kan.liang
2016-11-23 20:06 ` Peter Zijlstra
2016-11-23 20:09 ` Liang, Kan
2016-11-23 9:44 ` [PATCH 04/14] perf/x86: output side-band events overhead kan.liang
2016-11-23 20:06 ` Peter Zijlstra
2016-11-24 16:21 ` Mark Rutland
2016-11-24 19:40 ` Liang, Kan
2016-11-23 9:44 ` [PATCH 05/14] perf tools: handle PERF_RECORD_OVERHEAD record type kan.liang
2016-11-23 22:35 ` Jiri Olsa
2016-11-23 22:58 ` Jiri Olsa
2016-11-23 9:44 ` [PATCH 06/14] perf tools: show NMI overhead kan.liang
2016-11-23 22:51 ` Jiri Olsa
2016-11-24 13:37 ` Liang, Kan
2016-11-24 15:27 ` Jiri Olsa
2016-11-24 23:20 ` Namhyung Kim
2016-11-24 23:45 ` Jiri Olsa
2016-11-25 0:21 ` Andi Kleen
2016-11-23 22:52 ` Jiri Olsa
2016-11-23 22:52 ` Jiri Olsa
2016-11-23 9:44 ` [PATCH 07/14] perf tools: show multiplexing overhead kan.liang
2016-11-23 9:44 ` [PATCH 08/14] perf tools: show side-band events overhead kan.liang
2016-11-23 9:44 ` [PATCH 09/14] perf tools: make get_nsecs visible for buildin files kan.liang
2016-11-23 9:44 ` [PATCH 10/14] perf tools: introduce PERF_RECORD_USER_OVERHEAD kan.liang
2016-11-23 9:44 ` [PATCH 11/14] perf tools: record write data overhead kan.liang
2016-11-23 23:02 ` Jiri Olsa
2016-11-23 23:06 ` Jiri Olsa
2016-11-23 9:44 ` [PATCH 12/14] perf tools: record elapsed time kan.liang
2016-11-23 9:44 ` [PATCH 13/14] perf tools: warn on high overhead kan.liang
2016-11-23 20:25 ` Andi Kleen
2016-11-23 22:03 ` Liang, Kan
2016-11-25 20:42 ` Andi Kleen
2016-11-23 9:44 ` [PATCH 14/14] perf script: show overhead events kan.liang
2016-11-23 23:17 ` Jiri Olsa
2016-11-23 23:18 ` Jiri Olsa
2016-11-23 23:19 ` Jiri Olsa
2016-11-23 23:22 ` Jiri Olsa
2016-11-24 4:27 ` [PATCH 00/14] export perf overheads information Ingo Molnar
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