From 14b22ae028de56cca980171db625d1e9925c8fba Mon Sep 17 00:00:00 2001 From: Ganapatrao Kulkarni Date: Thu, 24 Aug 2017 16:30:58 +0530 Subject: perf pmu: Add helper function is_pmu_core to detect PMU CORE devices On some platforms, PMU core devices sysfs name is not cpu. Adding function is_pmu_core to detect PMU core devices using core device specific hints in sysfs. For arm64 platforms, all core devices have file "cpus" in sysfs. Signed-off-by: Ganapatrao Kulkarni Tested-by: Shaokun Zhang Tested-by: Jin Yao Acked-by: Will Deacon Link: https://lkml.kernel.org/n/tip-y1woxt1k2pqqwpprhonnft2s@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/pmu.c | 39 +++++++++++++++++++++++++++++++++++---- 1 file changed, 35 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 4e7dd3a0f123..732ff579ec65 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -536,6 +536,34 @@ static bool pmu_is_uncore(const char *name) return !!cpus; } +/* + * PMU CORE devices have different name other than cpu in sysfs on some + * platforms. looking for possible sysfs files to identify as core device. + */ +static int is_pmu_core(const char *name) +{ + struct stat st; + char path[PATH_MAX]; + const char *sysfs = sysfs__mountpoint(); + + if (!sysfs) + return 0; + + /* Look for cpu sysfs (x86 and others) */ + scnprintf(path, PATH_MAX, "%s/bus/event_source/devices/cpu", sysfs); + if ((stat(path, &st) == 0) && + (strncmp(name, "cpu", strlen("cpu")) == 0)) + return 1; + + /* Look for cpu sysfs (specific to arm) */ + scnprintf(path, PATH_MAX, "%s/bus/event_source/devices/%s/cpus", + sysfs, name); + if (stat(path, &st) == 0) + return 1; + + return 0; +} + /* * Return the CPU id as a raw string. * @@ -609,7 +637,6 @@ static void pmu_add_cpu_aliases(struct list_head *head, struct perf_pmu *pmu) */ i = 0; while (1) { - const char *pname; pe = &map->table[i++]; if (!pe->name) { @@ -618,9 +645,13 @@ static void pmu_add_cpu_aliases(struct list_head *head, struct perf_pmu *pmu) break; } - pname = pe->pmu ? pe->pmu : "cpu"; - if (strncmp(pname, name, strlen(pname))) - continue; + if (!is_pmu_core(name)) { + /* check for uncore devices */ + if (pe->pmu == NULL) + continue; + if (strncmp(pe->pmu, name, strlen(pe->pmu))) + continue; + } /* need type casts to override 'const' */ __perf_pmu__new_alias(head, NULL, (char *)pe->name, -- cgit v1.2.3