lkml.org 
[lkml]   [2024]   [Mar]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC PATCH v5 1/6] perf stat: Parse and find tpebs events when parsing metrics to prepare for perf record sampling
On Thu, Mar 28, 2024 at 11:43 PM Wang, Weilin <weilin.wang@intel.com> wrote:
>
>
>
> > -----Original Message-----
> > From: Namhyung Kim <namhyung@kernel.org>
> > Sent: Thursday, March 28, 2024 10:46 PM
> > To: Wang, Weilin <weilin.wang@intel.com>
> > Cc: Ian Rogers <irogers@google.com>; Arnaldo Carvalho de Melo
> > <acme@kernel.org>; Peter Zijlstra <peterz@infradead.org>; Ingo Molnar
> > <mingo@redhat.com>; Alexander Shishkin
> > <alexander.shishkin@linux.intel.com>; Jiri Olsa <jolsa@kernel.org>; Hunter,
> > Adrian <adrian.hunter@intel.com>; Kan Liang <kan.liang@linux.intel.com>;
> > linux-perf-users@vger.kernel.org; linux-kernel@vger.kernel.org; Taylor, Perry
> > <perry.taylor@intel.com>; Alt, Samantha <samantha.alt@intel.com>; Biggers,
> > Caleb <caleb.biggers@intel.com>
> > Subject: Re: [RFC PATCH v5 1/6] perf stat: Parse and find tpebs events when
> > parsing metrics to prepare for perf record sampling
> >
> > On Tue, Mar 26, 2024 at 1:29 PM <weilin.wang@intel.com> wrote:
> > >
> > > From: Weilin Wang <weilin.wang@intel.com>
> > >
> > > Metrics that use tpebs values would use the :retire_latency keyword in
> > > formulas. We put all these events into a list and pass the list to perf
> > > record to collect their retire latency value.
> > >
> > > Signed-off-by: Weilin Wang <weilin.wang@intel.com>
> > > Reviewed-by: Ian Rogers <irogers@google.com>
> > > ---
> > [SNIP]
> > > @@ -681,8 +685,56 @@ static int metricgroup__build_event_string(struct
> > strbuf *events,
> > > hashmap__for_each_entry(ctx->ids, cur, bkt) {
> > > const char *sep, *rsep, *id = cur->pkey;
> > > enum perf_tool_event ev;
> > > + /*
> > > + * Parse and search for event name with retire_latency modifier.
> > > + * If found, put event name into the tpebs_events list. This list
> > > + * of events will be passed to perf record for sampling to get
> > > + * their reitre_latency value.
> > > + * Search for ":R" in event name without "@". Search for the
> > > + * last "@R" in event name with "@".
> >
> > What is the retire_latency modifier exactly?
> > Why do you search for :R and @R? What's the difference?
> > Why don't you search for "retire_latency"?
>
> We decided to use R as the modifier for retire_latency in one of the previous
> version of code review. Therefore, the code searches for R instead of "retire_latency".
>
> It should search for :R in usual cases. But in hybrid platform, event name might be in
> format like cpu_core@event_name@R.

Ok, thanks for the explanation. Please update the commit message and
the comment with this info.

Thanks,
Namhyung

\
 
 \ /
  Last update: 2024-05-27 16:14    [W:0.042 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site