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Message-Id: <20220208211637.2221872-11-eranian@google.com>
Date: Tue, 8 Feb 2022 13:16:35 -0800
From: Stephane Eranian <eranian@...gle.com>
To: linux-kernel@...r.kernel.org
Cc: peterz@...radead.org, kim.phillips@....com, acme@...hat.com,
jolsa@...hat.com, songliubraving@...com
Subject: [PATCH v6 10/12] perf tools: Improve IBS error handling
From: Kim Phillips <kim.phillips@....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.
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.
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@....com>
Cc: Arnaldo Carvalho de Melo <acme@...hat.com>
Cc: Alexander Shishkin <alexander.shishkin@...ux.intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@...cle.com>
Cc: Ian Rogers <irogers@...gle.com>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Joao Martins <joao.m.martins@...cle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Cc: Mark Rutland <mark.rutland@....com>
Cc: Michael Petlan <mpetlan@...hat.com>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Robert Richter <robert.richter@....com>
Cc: Stephane Eranian <eranian@...gle.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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