Messages in this thread Patch in this message | | | From | Ganapatrao Kulkarni <> | Subject | [PATCH v6 3/4] perf utils: Add helper function is_pmu_core to detect PMU CORE devices | Date | Thu, 24 Aug 2017 17:33:48 +0530 |
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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.
Tested-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com> --- 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 aefdbd1..c2fe70f 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -506,6 +506,34 @@ static struct cpu_map *pmu_cpumask(const char *name) } /* + * 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. * * Each architecture should provide a more precise id string that @@ -558,15 +586,18 @@ static void pmu_add_cpu_aliases(struct list_head *head, const char *name, */ i = 0; while (1) { - const char *pname; pe = &map->table[i++]; if (!pe->name) 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, -- 2.9.4
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