From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Andi Kleen <ak@linux.intel.com>, Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
Jiri Olsa <jolsa@redhat.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Ingo Molnar <mingo@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
LKML <linux-kernel@vger.kernel.org>,
Stephane Eranian <eranian@google.com>,
Ian Rogers <irogers@google.com>,
alexander.shishkin@linux.intel.com
Subject: Re: [RFC] perf evlist: Warn if event group has mixed sw/hw events
Date: Mon, 26 Oct 2020 17:49:07 +0200 [thread overview]
Message-ID: <87y2jtq970.fsf@ashishki-desk.ger.corp.intel.com> (raw)
In-Reply-To: <20201026152108.GW466880@tassilo.jf.intel.com>
Andi Kleen <ak@linux.intel.com> writes:
> On Mon, Oct 26, 2020 at 11:19:37PM +0900, Namhyung Kim wrote:
>> This patch just added a warning before running it. I'd really want to
>> fix the kernel if possible but don't have a good idea. Thoughts?
>
> The easiest fix would be some multi threading in perf stat opening, then then
> extra latencies could be mostly hidden. One thread per group would probably
> be overkill, but just a few threads would lower the penalty significantly.
>
> I think that would be better than this patch and it's likely not that much
> more complicated, as this is already a lot of code.
>
>> +{
>> + const char *known_sw_pmu[] = {
>> + "software", "tracepoint", "breakpoint", "kprobe", "uprobe", "msr"
>
> That's a non scalable approach. New pmus get added regularly. It would be better to
> indicate this in a generic way from the kernel.
That, and also, intel_pt is a software PMU and a few of its features
depend on intel_pt/.../ being a group leader.
Regards,
--
Alex
next prev parent reply other threads:[~2020-10-26 15:49 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-26 14:19 Namhyung Kim
2020-10-26 15:21 ` Andi Kleen
2020-10-26 15:49 ` Alexander Shishkin [this message]
2020-10-27 4:45 ` Namhyung Kim
2020-10-27 4:43 ` Namhyung Kim
2020-11-01 8:23 ` [perf evlist] 5f2344c367: perf-sanity-tests.'import_perf'_in_python.fail kernel test robot
2020-11-05 8:40 ` [RFC] perf evlist: Warn if event group has mixed sw/hw events Stephane Eranian
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