Commit 98b7ce0e authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf intel-pt: Use perf_pmu__scan_file_at() if possible 



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: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Acked-by: default avatarIan 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 3a69672e

tools/perf/arch/x86/util/intel-pt.c

+32 −20
Original line number Diff line number Diff line
@@ -194,15 +194,18 @@ 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",

	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",

		if (perf_pmu__scan_file_at(intel_pt_pmu, dirfd, "caps/mtc_periods", "%x",

					   &mtc_periods) != 1)

			mtc_periods = 0;

		if (mtc_periods) {
@@ -212,12 +215,12 @@ static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu) 
		}

	}



	if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_cyc", "%d",

	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",

		if (perf_pmu__scan_file_at(intel_pt_pmu, dirfd, "caps/psb_periods", "%x",

					   &psb_periods) != 1)

			psb_periods = 0;

		if (psb_periods) {
@@ -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,