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Code Issues Releases Wiki Activity

perf intel-pt: Use perf_pmu__scan_file_at() if possible

Browse source 
Intel-PT calls perf_pmu__scan_file() a lot, let's use relative address
when it accesses multiple files at one place.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230331202949.810326-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2023-03-31 13:29:49 -07:00 committed by Arnaldo Carvalho de Melo
parent 3a69672e88
commit 98b7ce0ed8
1 changed files with 32 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

52
tools/perf/arch/x86/util/intel-pt.c
View file

@ -194,16 +194,19 @@ static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)
int pos = 0;
u64 config;
char c;
int dirfd;
dirfd = perf_pmu__event_source_devices_fd();
pos += scnprintf(buf + pos, sizeof(buf) - pos, "tsc");
if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc", "%d",
&mtc) != 1)
if (perf_pmu__scan_file_at(intel_pt_pmu, dirfd, "caps/mtc", "%d",
&mtc) != 1)
mtc = 1;
if (mtc) {
if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc_periods", "%x",
&mtc_periods) != 1)
if (perf_pmu__scan_file_at(intel_pt_pmu, dirfd, "caps/mtc_periods", "%x",
&mtc_periods) != 1)
mtc_periods = 0;
if (mtc_periods) {
mtc_period = intel_pt_pick_bit(mtc_periods, 3);
@ -212,13 +215,13 @@ static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)
}
}
if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_cyc", "%d",
&psb_cyc) != 1)
if (perf_pmu__scan_file_at(intel_pt_pmu, dirfd, "caps/psb_cyc", "%d",
&psb_cyc) != 1)
psb_cyc = 1;
if (psb_cyc && mtc_periods) {
if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_periods", "%x",
&psb_periods) != 1)
if (perf_pmu__scan_file_at(intel_pt_pmu, dirfd, "caps/psb_periods", "%x",
&psb_periods) != 1)
psb_periods = 0;
if (psb_periods) {
psb_period = intel_pt_pick_bit(psb_periods, 3);
@ -227,8 +230,8 @@ static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)
}
}
if (perf_pmu__scan_file(intel_pt_pmu, "format/pt", "%c", &c) == 1 &&
perf_pmu__scan_file(intel_pt_pmu, "format/branch", "%c", &c) == 1)
if (perf_pmu__scan_file_at(intel_pt_pmu, dirfd, "format/pt", "%c", &c) == 1 &&
perf_pmu__scan_file_at(intel_pt_pmu, dirfd, "format/branch", "%c", &c) == 1)
pos += scnprintf(buf + pos, sizeof(buf) - pos, ",pt,branch");
pr_debug2("%s default config: %s\n", intel_pt_pmu->name, buf);
@ -236,6 +239,7 @@ static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)
intel_pt_parse_terms(intel_pt_pmu->name, &intel_pt_pmu->format, buf,
&config);
close(dirfd);
return config;
}
@ -488,7 +492,7 @@ static void intel_pt_valid_str(char *str, size_t len, u64 valid)
}
}
static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu,
static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu, int dirfd,
const char *caps, const char *name,
const char *supported, u64 config)
{
@ -498,11 +502,11 @@ static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu,
u64 bits;
int ok;
if (perf_pmu__scan_file(intel_pt_pmu, caps, "%llx", &valid) != 1)
if (perf_pmu__scan_file_at(intel_pt_pmu, dirfd, caps, "%llx", &valid) != 1)
valid = 0;
if (supported &&
perf_pmu__scan_file(intel_pt_pmu, supported, "%d", &ok) == 1 && !ok)
perf_pmu__scan_file_at(intel_pt_pmu, dirfd, supported, "%d", &ok) == 1 && !ok)
valid = 0;
valid |= 1;
@ -531,37 +535,45 @@ static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu,
static int intel_pt_validate_config(struct perf_pmu *intel_pt_pmu,
struct evsel *evsel)
{
int err;
int err, dirfd;
char c;
if (!evsel)
return 0;
dirfd = perf_pmu__event_source_devices_fd();
if (dirfd < 0)
return dirfd;
/*
* 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 &&
if (perf_pmu__scan_file_at(intel_pt_pmu, dirfd, "format/pt", "%c", &c) == 1 &&
!(evsel->core.attr.config & 1)) {
pr_warning("pt=0 doesn't make sense, forcing pt=1\n");
evsel->core.attr.config |= 1;
}
err = intel_pt_val_config_term(intel_pt_pmu, "caps/cycle_thresholds",
err = intel_pt_val_config_term(intel_pt_pmu, dirfd, "caps/cycle_thresholds",
"cyc_thresh", "caps/psb_cyc",
evsel->core.attr.config);
if (err)
return err;
goto out;
err = intel_pt_val_config_term(intel_pt_pmu, "caps/mtc_periods",
err = intel_pt_val_config_term(intel_pt_pmu, dirfd, "caps/mtc_periods",
"mtc_period", "caps/mtc",
evsel->core.attr.config);
if (err)
return err;
goto out;
return intel_pt_val_config_term(intel_pt_pmu, "caps/psb_periods",
err = intel_pt_val_config_term(intel_pt_pmu, dirfd, "caps/psb_periods",
"psb_period", "caps/psb_cyc",
evsel->core.attr.config);
out:
close(dirfd);
return err;
}
static void intel_pt_config_sample_mode(struct perf_pmu *intel_pt_pmu,