lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20171120155345.GB13495@krava>
Date:   Mon, 20 Nov 2017 16:53:45 +0100
From:   Jiri Olsa <jolsa@...hat.com>
To:     Andi Kleen <andi@...stfloor.org>
Cc:     acme@...nel.org, jolsa@...nel.org, linux-kernel@...r.kernel.org,
        Andi Kleen <ak@...ux.intel.com>
Subject: Re: [PATCH v3 3/3] perf, tools, script: Allow computing metrics in
 perf script

On Mon, Nov 20, 2017 at 07:35:05AM -0800, Andi Kleen wrote:
> On Mon, Nov 20, 2017 at 10:04:19AM +0100, Jiri Olsa wrote:
> > On Fri, Nov 17, 2017 at 01:43:00PM -0800, Andi Kleen wrote:
> > 
> > SNIP
> > 
> > > ---
> > >  tools/perf/Documentation/perf-script.txt | 10 +++-
> > >  tools/perf/builtin-script.c              | 97 +++++++++++++++++++++++++++++++-
> > >  tools/perf/util/metricgroup.c            |  4 ++
> > >  3 files changed, 108 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
> > > index 2811fcf684cb..974ceb12c7f3 100644
> > > --- a/tools/perf/Documentation/perf-script.txt
> > > +++ b/tools/perf/Documentation/perf-script.txt
> > > @@ -117,7 +117,7 @@ OPTIONS
> > >          Comma separated list of fields to print. Options are:
> > >          comm, tid, pid, time, cpu, event, trace, ip, sym, dso, addr, symoff,
> > >          srcline, period, iregs, uregs, brstack, brstacksym, flags, bpf-output, brstackinsn,
> > > -        brstackoff, callindent, insn, insnlen, synth, phys_addr.
> > > +	brstackoff, callindent, insn, insnlen, synth, phys_addr, metric.
> > >          Field list can be prepended with the type, trace, sw or hw,
> > >          to indicate to which event type the field list applies.
> > >          e.g., -F sw:comm,tid,time,ip,sym  and -F trace:time,cpu,trace
> > > @@ -217,6 +217,14 @@ OPTIONS
> > >  
> > >  	The brstackoff field will print an offset into a specific dso/binary.
> > >  
> > > +	With the metric option perf script can compute metrics for
> > > +	sampling periods, similar to perf stat. This requires
> > > +	specifying a group with multiple metrics with the :S option
> > > +	for perf record. perf will sample on the first event, and
> > > +	compute metrics for all the events in the group. Please note
> > > +	that the metric computed is averaged over the whole sampling
> > > +	period, not just for the sample point.
> > 
> > hum, is it? I see you call perf_stat__reset_shadow_stats for every
> > group start.. which I'd think means you see metric for current
> > leader sample point
> 
> Yes it is.
> 
> It's for the complete sampling period because it is computed
> over the delta from the last sample to the previous sample.
> 
> There isn't really a metric at a point, it is always over a interval.

agreed, it's the count we meassured from the last sample.. but the
'averaged' word above implies to me we compute some average over the
'sampling' period, which we dont do

jirka

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ