Messages in this thread | | | Date | Mon, 28 Oct 2019 23:01:37 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH v3 1/7] perf pmu: Use file system cache to optimize sysfs access |
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On Fri, Oct 25, 2019 at 11:14:11AM -0700, Andi Kleen wrote:
SNIP
> if (pmu_aliases_parse(path, head)) > return -1; > @@ -525,7 +524,6 @@ static int pmu_alias_terms(struct perf_pmu_alias *alias, > */ > static int pmu_type(const char *name, __u32 *type) > { > - struct stat st; > char path[PATH_MAX]; > FILE *file; > int ret = 0; > @@ -537,7 +535,7 @@ static int pmu_type(const char *name, __u32 *type) > snprintf(path, PATH_MAX, > "%s" EVENT_SOURCE_DEVICE_PATH "%s/type", sysfs, name); > > - if (stat(path, &st) < 0) > + if (access(path, R_OK) < 0)
why not file_available call in here?
jirka
> return -1; > > file = fopen(path, "r"); > @@ -628,14 +626,11 @@ static struct perf_cpu_map *pmu_cpumask(const char *name) > static bool pmu_is_uncore(const char *name) > { > char path[PATH_MAX]; > - struct perf_cpu_map *cpus; > - const char *sysfs = sysfs__mountpoint(); > + const char *sysfs; > > + sysfs = sysfs__mountpoint(); > snprintf(path, PATH_MAX, CPUS_TEMPLATE_UNCORE, sysfs, name);
SNIP
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