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authorAdrian Hunter <adrian.hunter@intel.com>2018-11-26 14:12:52 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-01-26 09:37:04 +0100
commite5ae88fabeab15a87ea4663d7a9ca98a9b593b74 (patch)
tree5c319944bc411788b8abece3080a512cddf24b03
parent035438452f85412438be0f6b4dae88b32353cfac (diff)
download96b-common-e5ae88fabeab15a87ea4663d7a9ca98a9b593b74.tar.gz
perf intel-pt: Fix error with config term "pt=0"
[ Upstream commit 1c6f709b9f96366cc47af23c05ecec9b8c0c392d ] Users should never use 'pt=0', but if they do it may give a meaningless error: $ perf record -e intel_pt/pt=0/u uname Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (intel_pt/pt=0/u). Fix that by forcing 'pt=1'. Committer testing: # perf record -e intel_pt/pt=0/u uname Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (intel_pt/pt=0/u). /bin/dmesg | grep -i perf may provide additional information. # perf record -e intel_pt/pt=0/u uname pt=0 doesn't make sense, forcing pt=1 Linux [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.020 MB perf.data ] # Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/b7c5b4e5-9497-10e5-fd43-5f3e4a0fe51d@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--tools/perf/arch/x86/util/intel-pt.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
index db0ba8caf5a2..ba8ecaf52200 100644
--- a/tools/perf/arch/x86/util/intel-pt.c
+++ b/tools/perf/arch/x86/util/intel-pt.c
@@ -524,10 +524,21 @@ static int intel_pt_validate_config(struct perf_pmu *intel_pt_pmu,
struct perf_evsel *evsel)
{
int err;
+ char c;
if (!evsel)
return 0;
+ /*
+ * If supported, force pass-through config term (pt=1) even if user
+ * sets pt=0, which avoids senseless kernel errors.
+ */
+ if (perf_pmu__scan_file(intel_pt_pmu, "format/pt", "%c", &c) == 1 &&
+ !(evsel->attr.config & 1)) {
+ pr_warning("pt=0 doesn't make sense, forcing pt=1\n");
+ evsel->attr.config |= 1;
+ }
+
err = intel_pt_val_config_term(intel_pt_pmu, "caps/cycle_thresholds",
"cyc_thresh", "caps/psb_cyc",
evsel->attr.config);