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authorKim Phillips <kim.phillips@amd.com>2022-03-22 15:15:15 -0700
committerArnaldo Carvalho de Melo <acme@redhat.com>2022-03-26 10:55:58 -0300
commitab0809af0bee88b689ba289ec8c40aa2be3a17ec (patch)
treea6eb8069a5afcb48f83d3bceb8fecfe3d1b9da48 /tools
parentb58230de3ccdc2f4566d576b34b5f1feceea2e73 (diff)
perf evsel: Improve AMD IBS (Instruction-Based Sampling) error handling messages
Improve the error message returned on failed perf_event_open() on AMD systems when using IBS (Instruction-Based Sampling). Output of executing 'perf record -e ibs_op// true' as a non root user BEFORE this patch (perf will add the 'u' modifier at the end to exclude kernel/hypervisor sampling): 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. Output after: AMD IBS can't 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. Output after: Error: Invalid event (ibs_op//) in per-thread mode, enable system wide with '-a'. Folowing the suggestion: $ sudo perf record -a -e ibs_op// true [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.664 MB perf.data (194 samples) ] $ Signed-off-by: Kim Phillips <kim.phillips@amd.com> Tested-by: 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: Jiri Olsa <jolsa@kernel.org> Cc: João 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: Rafael J. Wysocki <rafael@kernel.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Robert Richter <robert.richter@amd.com> Cc: Sandipan Das <sandipan.das@amd.com> Cc: Song Liu <songliubraving@fb.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20220322221517.2510440-12-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/evsel.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 5ecf8f836f30..2a1729e7aee4 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2847,9 +2847,23 @@ 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
+ || (evsel->pmu_name && !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;
@@ -2953,6 +2967,17 @@ 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. "