Messages in this thread | | | From | "Wang, Weilin" <> | Subject | RE: [RFC PATCH v8 3/7] perf stat: Fork and launch perf record when perf stat needs to get retire latency value for a metric. | Date | Tue, 21 May 2024 16:23:24 +0000 |
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> -----Original Message----- > From: Namhyung Kim <namhyung@kernel.org> > Sent: Monday, May 20, 2024 10:43 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 v8 3/7] perf stat: Fork and launch perf record when > perf stat needs to get retire latency value for a metric. > > Hello, > > On Mon, May 20, 2024 at 5:10 PM Wang, Weilin <weilin.wang@intel.com> > wrote: > > > > > > > > > -----Original Message----- > > > From: Namhyung Kim <namhyung@kernel.org> > > > Sent: Friday, May 17, 2024 2:43 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 v8 3/7] perf stat: Fork and launch perf record > when > > > perf stat needs to get retire latency value for a metric. > > > > > > On Tue, May 14, 2024 at 10:44 PM <weilin.wang@intel.com> wrote: > > > > > > > > From: Weilin Wang <weilin.wang@intel.com> > > > > > > > > When retire_latency value is used in a metric formula, perf stat would > fork a > > > > perf record process with "-e" and "-W" options. Perf record will collect > > > > required retire_latency values in parallel while perf stat is collecting > > > > counting values. > > > > > > > > At the point of time that perf stat stops counting, it would send sigterm > > > signal > > > > to perf record process and receiving sampling data back from perf record > > > from a > > > > pipe. Perf stat will then process the received data to get retire latency > data > > > > and calculate metric result. > > > > > > > > Another thread is required to synchronize between perf stat and perf > record > > > > when we pass data through pipe. > > > > > > > > Signed-off-by: Weilin Wang <weilin.wang@intel.com> > > > > Reviewed-by: Ian Rogers <irogers@google.com> > > > > --- > > > [SNIP] > > > > diff --git a/tools/perf/util/intel-tpebs.c b/tools/perf/util/intel-tpebs.c > > > > new file mode 100644 > > > > index 000000000000..4b7a98794fae > > > > --- /dev/null > > > > +++ b/tools/perf/util/intel-tpebs.c > > > > @@ -0,0 +1,285 @@ > > > > +// SPDX-License-Identifier: GPL-2.0-only > > > > +/* > > > > + * intel_pt.c: Intel Processor Trace support > > > > + * Copyright (c) 2013-2015, Intel Corporation. > > > > > > This needs some updates. :) > > > > > > > > > > + */ > > > > + > > > > + > > > > +#include <sys/param.h> > > > > +#include <subcmd/run-command.h> > > > > +#include <thread.h> > > > > +#include "intel-tpebs.h" > > > > +#include <linux/list.h> > > > > +#include <linux/zalloc.h> > > > > +#include <linux/err.h> > > > > +#include "sample.h" > > > > +#include "debug.h" > > > > +#include "evlist.h" > > > > +#include "evsel.h" > > > > +#include "session.h" > > > > +#include "tool.h" > > > > +#include "metricgroup.h" > > > > +#include <sys/stat.h> > > > > +#include <sys/file.h> > > > > + > > > > + > > > > + > > > > +#define PERF_DATA "-" > > > > +#define CONTROL "/tmp/control" > > > > +#define ACK "/tmp/ack" > > > > +pthread_t reader_thread; > > > > +struct child_process *cmd; > > > > +struct perf_stat_config *stat_config; > > > > > > static ? > > > > > > > + > > > > +static int get_perf_record_args(const char **record_argv) > > > > +{ > > > > + int i = 0; > > > > + struct tpebs_retire_lat *e; > > > > + > > > > + pr_debug("Prepare perf record for retire_latency\n"); > > > > + > > > > + record_argv[i++] = "perf"; > > > > + record_argv[i++] = "record"; > > > > + record_argv[i++] = "-W"; > > > > + record_argv[i++] = "--synth=no"; > > > > > > Unfortunately this still synthesizes MMAP records for the kernel > > > and modules. As we don't care about them and just want to > > > minimize the overhead at the beginning, we can add > > > "--tail-synthesize" too. > > > > Hi Namhyung, > > > > I'm trying out the "--tail-synthesize" option but failed to get it work > > correctly. Could you please take a look at this command and let me > > know what's the problem? > > > > "perf record -e cycles:p --synth=no --tail-synthesize -W -a -o - sleep 1 | perf > script -F retire_lat -i -". > > > > I got an error "0x40 [0x40]: failed to process type: 9" when run this > command. > > > > If I run the command in two steps without pipe, they work fine. > > Hmm... it may not work with pipes. Let's go without the > tail-synthesize then. Sorry for the noise.
No problem.
Thanks, Weilin > > Thanks, > Namhyung
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