Messages in this thread Patch in this message | | | Date | Wed, 9 Feb 2022 12:47:46 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v6 10/12] perf tools: Improve IBS error handling |
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Em Tue, Feb 08, 2022 at 01:16:35PM -0800, Stephane Eranian escreveu: > From: Kim Phillips <kim.phillips@amd.com> > > improve the error message returned on failed perf_event_open() on AMD when > using IBS. > > Output of executing 'perf record -e ibs_op// true' BEFORE this patch: > > The sys_perf_event_open() syscall returned with 22 (Invalid argument)for event (ibs_op//u). > /bin/dmesg | grep -i perf may provide additional information.
Humm, here on a
$ grep -m1 'model name' /proc/cpuinfo model name : AMD Ryzen 9 5950X 16-Core Processor $ ls -la /sys/devices/ibs_op total 0 drwxr-xr-x. 4 root root 0 Feb 9 07:12 . drwxr-xr-x. 21 root root 0 Feb 9 07:12 .. drwxr-xr-x. 2 root root 0 Feb 9 12:17 format -rw-r--r--. 1 root root 4096 Feb 9 12:21 perf_event_mux_interval_ms drwxr-xr-x. 2 root root 0 Feb 9 12:21 power lrwxrwxrwx. 1 root root 0 Feb 9 07:12 subsystem -> ../../bus/event_source -r--r--r--. 1 root root 4096 Feb 9 12:17 type -rw-r--r--. 1 root root 4096 Feb 9 07:12 uevent $ cat /sys/devices/ibs_op/type 9 $
Running without this patch:
$ uname -a Linux five 5.15.14-100.fc34.x86_64 #1 SMP Tue Jan 11 16:53:51 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux $
$ cat /etc/redhat-release Fedora release 34 (Thirty Four) $
$ perf record -e ibs_op// true Error: Invalid event (ibs_op//u) in per-thread mode, enable system wide with '-a'. $
Trying with system wide:
$ perf record -a -e ibs_op// true Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (ibs_op//u). /bin/dmesg | grep -i perf may provide additional information. $
So you're missing -a in all examples? Am I missing something?
> Output after: > > AMD IBS cannot exclude kernel events. Try running at a higher privilege level. > > Output of executing 'sudo perf record -e ibs_op// true' BEFORE this patch: > > Error: > The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (ibs_op//). > /bin/dmesg | grep -i perf may provide additional information.
Here, as root:
[root@five ~]# perf record -e ibs_op// true Error: Invalid event (ibs_op//) in per-thread mode, enable system wide with '-a'. [root@five ~]# perf record -a -e ibs_op// true [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.482 MB perf.data (175 samples) ] [root@five ~]#
- Arnaldo > Output after: > > Error: > AMD IBS may only be available in system-wide/per-cpu mode. Try using -a, or -C and workload affinity > > Signed-off-by: Kim Phillips <kim.phillips@amd.com> > Cc: Arnaldo Carvalho de Melo <acme@redhat.com> > Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> > Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> > Cc: Ian Rogers <irogers@google.com> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Jiri Olsa <jolsa@redhat.com> > Cc: Joao Martins <joao.m.martins@oracle.com> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Michael Petlan <mpetlan@redhat.com> > Cc: Namhyung Kim <namhyung@kernel.org> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Robert Richter <robert.richter@amd.com> > Cc: Stephane Eranian <eranian@google.com> > --- > tools/perf/util/evsel.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > index 22d3267ce294..d42f63a484df 100644 > --- a/tools/perf/util/evsel.c > +++ b/tools/perf/util/evsel.c > @@ -2847,9 +2847,22 @@ static bool find_process(const char *name) > return ret ? false : true; > } > > +static bool is_amd(const char *arch, const char *cpuid) > +{ > + return arch && !strcmp("x86", arch) && cpuid && strstarts(cpuid, "AuthenticAMD"); > +} > + > +static bool is_amd_ibs(struct evsel *evsel) > +{ > + return evsel->core.attr.precise_ip || !strncmp(evsel->pmu_name, "ibs", 3); > +} > + > int evsel__open_strerror(struct evsel *evsel, struct target *target, > int err, char *msg, size_t size) > { > + struct perf_env *env = evsel__env(evsel); > + const char *arch = perf_env__arch(env); > + const char *cpuid = perf_env__cpuid(env); > char sbuf[STRERR_BUFSIZE]; > int printed = 0, enforced = 0; > > @@ -2949,6 +2962,17 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target, > return scnprintf(msg, size, > "Invalid event (%s) in per-thread mode, enable system wide with '-a'.", > evsel__name(evsel)); > + if (is_amd(arch, cpuid)) { > + if (is_amd_ibs(evsel)) { > + if (evsel->core.attr.exclude_kernel) > + return scnprintf(msg, size, > + "AMD IBS can't exclude kernel events. Try running at a higher privilege level."); > + if (!evsel->core.system_wide) > + return scnprintf(msg, size, > + "AMD IBS may only be available in system-wide/per-cpu mode. Try using -a, or -C and workload affinity"); > + } > + } > + > break; > case ENODATA: > return scnprintf(msg, size, "Cannot collect data source with the load latency event alone. " > -- > 2.35.0.263.gb82422642f-goog
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- Arnaldo
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