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Message-ID: <20240905202426.2690105-10-namhyung@kernel.org>
Date: Thu, 5 Sep 2024 13:24:25 -0700
From: Namhyung Kim <namhyung@...nel.org>
To: Arnaldo Carvalho de Melo <acme@...nel.org>,
Ian Rogers <irogers@...gle.com>,
Kan Liang <kan.liang@...ux.intel.com>
Cc: Jiri Olsa <jolsa@...nel.org>,
Adrian Hunter <adrian.hunter@...el.com>,
Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...nel.org>,
LKML <linux-kernel@...r.kernel.org>,
linux-perf-users@...r.kernel.org,
Ravi Bangoria <ravi.bangoria@....com>,
Mark Rutland <mark.rutland@....com>,
James Clark <james.clark@....com>,
Kajol Jain <kjain@...ux.ibm.com>,
Thomas Richter <tmricht@...ux.ibm.com>,
Atish Patra <atishp@...shpatra.org>,
Palmer Dabbelt <palmer@...osinc.com>,
Mingwei Zhang <mizhang@...gle.com>
Subject: [PATCH 09/10] perf tools: Check fallback error and order
The perf_event_open might fail due to various reasons, so blindly
reducing precise_ip level might not be the best way to deal with it.
It seems the kernel return -EOPNOTSUPP when PMU doesn't support the
given precise level. Let's try again with the correct error code.
This caused a problem on AMD, as it stops on precise_ip of 2 for IBS but
user events with exclude_kernel=1 cannot make progress. Let's add the
evsel__handle_error_quirks() to this case specially. I plan to work on
the kernel side to improve this situation but it'd still need some
special handling for IBS.
Signed-off-by: Namhyung Kim <namhyung@...nel.org>
---
tools/perf/util/evsel.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index c5df45bb74dfc1b5..895f45921da30bb2 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2404,6 +2404,20 @@ static bool evsel__detect_missing_features(struct evsel *evsel)
return false;
}
+static bool evsel__handle_error_quirks(struct evsel *evsel, int error)
+{
+ /* AMD IBS doesn't support exclude_kernel, forward it to core PMU */
+ if (error == -EINVAL && evsel->precise_max && evsel->core.attr.precise_ip &&
+ evsel->core.attr.exclude_kernel && x86__is_amd_cpu()) {
+ evsel->core.attr.precise_ip = 0;
+ pr_debug2_peo("removing precise_ip on AMD\n");
+ display_attr(&evsel->core.attr);
+ return true;
+ }
+
+ return false;
+}
+
static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
struct perf_thread_map *threads,
int start_cpu_map_idx, int end_cpu_map_idx)
@@ -2565,9 +2579,6 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
return 0;
try_fallback:
- if (evsel__precise_ip_fallback(evsel))
- goto retry_open;
-
if (evsel__ignore_missing_thread(evsel, perf_cpu_map__nr(cpus),
idx, threads, thread, err)) {
/* We just removed 1 thread, so lower the upper nthreads limit. */
@@ -2584,11 +2595,15 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
if (err == -EMFILE && rlimit__increase_nofile(&set_rlimit))
goto retry_open;
- if (err != -EINVAL || idx > 0 || thread > 0)
- goto out_close;
+ if (err == -EOPNOTSUPP && evsel__precise_ip_fallback(evsel))
+ goto retry_open;
- if (evsel__detect_missing_features(evsel))
+ if (err == -EINVAL && evsel__detect_missing_features(evsel))
goto fallback_missing_features;
+
+ if (evsel__handle_error_quirks(evsel, err))
+ goto retry_open;
+
out_close:
if (err)
threads->err_thread = thread;
--
2.46.0.469.g59c65b2a67-goog
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