Messages in this thread | | | Date | Mon, 3 Apr 2023 07:51:01 +0300 | Subject | Re: [PATCH 9/9] perf intel-pt: Use perf_pmu__scan_file_at() if possible | From | Adrian Hunter <> |
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On 31/03/23 23:29, Namhyung Kim wrote: > 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>
> --- > tools/perf/arch/x86/util/intel-pt.c | 52 ++++++++++++++++++----------- > 1 file changed, 32 insertions(+), 20 deletions(-) > > diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c > index 1e39a034cee9..2cff11de9d8a 100644 > --- a/tools/perf/arch/x86/util/intel-pt.c > +++ b/tools/perf/arch/x86/util/intel-pt.c > @@ -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,
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