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Message-ID: <20240904064131.2377873-7-namhyung@kernel.org>
Date: Tue, 3 Sep 2024 23:41:29 -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>,
Athira Rajeev <atrajeev@...ux.vnet.ibm.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 6/8] perf tools: Separate exclude_hv fallback
The exclude_hv was added to address branch stack samples on Intel PMUs.
As some other PMUs might not support that, let's separate the bit from
exclude_kernel to make sure it can add the bit only if required.
Signed-off-by: Namhyung Kim <namhyung@...nel.org>
---
tools/perf/util/evsel.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 6456c28326144528..0de0a72947db3f10 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -3389,10 +3389,16 @@ bool evsel__fallback(struct evsel *evsel, struct target *target, int err,
free(evsel->name);
evsel->name = new_name;
scnprintf(msg, msgsize, "kernel.perf_event_paranoid=%d, trying "
- "to fall back to excluding kernel and hypervisor "
- " samples", paranoid);
+ "to fall back to excluding kernel samples", paranoid);
evsel->core.attr.exclude_kernel = 1;
- evsel->core.attr.exclude_hv = 1;
+
+ return true;
+ } else if (err == EACCES && !evsel->core.attr.exclude_hv &&
+ (paranoid = perf_event_paranoid()) > 1) {
+ /* Intel branch stack requires exclude_hv */
+ scnprintf(msg, msgsize, "kernel.perf_event_paranoid=%d, trying "
+ "to fall back to excluding hypervisor samples", paranoid);
+ evsel->core.attr.exclude_hv = 1;
return true;
}
--
2.46.0.469.g59c65b2a67-goog
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