Hi Arnaldo, On 2/9/2021 2:55 AM, Arnaldo Carvalho de Melo wrote:
Em Mon, Feb 08, 2021 at 07:25:25AM -0800, kan.li...@linux.intel.com escreveu:From: Jin Yao <yao....@linux.intel.com>We identify the cpu_core pmu and cpu_atom pmu by explicitly checking following files: For cpu_core, check: "/sys/bus/event_source/devices/cpu_core/cpus" For cpu_atom, check: "/sys/bus/event_source/devices/cpu_atom/cpus" If the 'cpus' file exists, the pmu exists. But in order not to hardcode the "cpu_core" and "cpu_atom", and make the code generic, if the path "/sys/bus/event_source/devices/cpu_xxx/cpus" exists, the hybrid pmu exists. All the detected hybrid pmus are linked to a global list 'perf_pmu__hybrid_pmus' and then next we just need to iterate the list by using perf_pmu__for_each_hybrid_pmus. Reviewed-by: Andi Kleen <a...@linux.intel.com> Signed-off-by: Jin Yao <yao....@linux.intel.com> --- tools/perf/util/pmu.c | 21 +++++++++++++++++++++ tools/perf/util/pmu.h | 7 +++++++ 2 files changed, 28 insertions(+) diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 0c25457..e97b121 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -27,6 +27,7 @@ #include "fncache.h"struct perf_pmu perf_pmu__fake;+LIST_HEAD(perf_pmu__hybrid_pmus);struct perf_pmu_format {char *name; @@ -633,11 +634,27 @@ static struct perf_cpu_map *pmu_cpumask(const char *name) return NULL; }+static bool pmu_is_hybrid(const char *name)+{ + char path[PATH_MAX]; + const char *sysfs; + + if (strncmp(name, "cpu_", 4)) + return false; + + sysfs = sysfs__mountpoint();Its extremely unlikely that sysfs isn't mounted, but if so, this will NULL deref, so please do as other sysfs__mountpoint() uses in tools/perf/util/pmu.c and check if sysfs is NULL, returning false, i.e. file isn't available.
Yes, I need to check the return value of sysfs__mountpoint(), something like.
sysfs = sysfs__mountpoint();
if (!sysfs)
return false;
+ snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, name); + return file_available(path); +} + static bool pmu_is_uncore(const char *name) { char path[PATH_MAX]; const char *sysfs;+ if (pmu_is_hybrid(name))+ return false; + sysfs = sysfs__mountpoint(); snprintf(path, PATH_MAX, CPUS_TEMPLATE_UNCORE, sysfs, name); return file_available(path); @@ -951,6 +968,7 @@ static struct perf_pmu *pmu_lookup(const char *name) pmu->is_uncore = pmu_is_uncore(name); if (pmu->is_uncore) pmu->id = pmu_id(name); + pmu->is_hybrid = pmu_is_hybrid(name); pmu->max_precise = pmu_max_precise(name); pmu_add_cpu_aliases(&aliases, pmu); pmu_add_sys_aliases(&aliases, pmu); @@ -962,6 +980,9 @@ static struct perf_pmu *pmu_lookup(const char *name) list_splice(&aliases, &pmu->aliases); list_add_tail(&pmu->list, &pmus);+ if (pmu->is_hybrid)+ list_add_tail(&pmu->hybrid_list, &perf_pmu__hybrid_pmus); + pmu->default_config = perf_pmu__get_default_config(pmu);return pmu;diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h index 0e724d5..99bdb5d 100644 --- a/tools/perf/util/pmu.h +++ b/tools/perf/util/pmu.h @@ -5,6 +5,7 @@ #include <linux/bitmap.h> #include <linux/compiler.h> #include <linux/perf_event.h> +#include <linux/list.h> #include <stdbool.h> #include "parse-events.h" #include "pmu-events/pmu-events.h" @@ -34,6 +35,7 @@ struct perf_pmu { __u32 type; bool selectable; bool is_uncore; + bool is_hybrid; bool auxtrace; int max_precise; struct perf_event_attr *default_config; @@ -42,9 +44,11 @@ struct perf_pmu { struct list_head aliases; /* HEAD struct perf_pmu_alias -> list */ struct list_head caps; /* HEAD struct perf_pmu_caps -> list */ struct list_head list; /* ELEM */ + struct list_head hybrid_list; };extern struct perf_pmu perf_pmu__fake;+extern struct list_head perf_pmu__hybrid_pmus;struct perf_pmu_info {const char *unit; @@ -124,4 +128,7 @@ int perf_pmu__convert_scale(const char *scale, char **end, double *sval);int perf_pmu__caps_parse(struct perf_pmu *pmu); +#define perf_pmu__for_each_hybrid_pmus(pmu) \singular, i.e. #define perf_pmu__for_each_hybrid_pmu(pmu) \
Got it. Will use perf_pmu__for_each_hybrid_pmu in next version. Thanks Jin Yao
+ list_for_each_entry(pmu, &perf_pmu__hybrid_pmus, hybrid_list) + #endif /* __PMU_H */ -- 2.7.4
