From 98b7ce0ed8f7a93ac0f6e0a0576c70093b669a71 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Fri, 31 Mar 2023 13:29:49 -0700 Subject: [PATCH] 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: Namhyung Kim Acked-by: Adrian Hunter Acked-by: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Leo Yan Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20230331202949.810326-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- 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 1e39a03..2cff11d 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 @@ out_err: 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, -- 2.7.4