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authorKan Liang <kan.liang@linux.intel.com>2021-09-02 14:59:54 +0800
committerArnaldo Carvalho de Melo <acme@redhat.com>2021-09-03 08:33:26 -0300
commit13d60ba0738b0532edab3e1492b2005d36ba0802 (patch)
treeb97de16b8668c52ddd05831e6865ab6086515020 /tools/perf/arch
parentc68b421d8ebe15b509144a6ec5a08ff7089a7dd5 (diff)
downloadlinux-13d60ba0738b0532edab3e1492b2005d36ba0802.tar.bz2
perf pmu: Add PMU alias support
A perf uncore PMU may have two PMU names, a real name and an alias. The alias is exported at /sys/bus/event_source/devices/uncore_*/alias. The perf tool should support the alias as well. Add alias_name in the struct perf_pmu to store the alias. For the PMU which doesn't have an alias. It's NULL. Introduce two X86 specific functions to retrieve the real name and the alias separately. Only go through the sysfs to retrieve the mapping between the real name and the alias once. The result is cached in a list, uncore_pmu_list. Nothing changed for the other ARCHs. With the patch, the perf tool can monitor the PMU with either the real name or the alias. Use the real name, $ perf stat -e uncore_cha_2/event=1/ -x, 4044879584,,uncore_cha_2/event=1/,2528059205,100.00,, Use the alias, $ perf stat -e uncore_type_0_2/event=1/ -x, 3659675336,,uncore_type_0_2/event=1/,2287306455,100.00,, Committer notes: Rename 'struct perf_pmu_alias_name' to 'pmu_alias', the 'perf_' prefix should be used for libperf, things inside just tools/perf/ are being moved away from that prefix. Also 'pmu_alias' is shorter and reflects the abstraction. Also don't use 'pmu' as the name for variables for that type, we should use that for the 'struct perf_pmu' variables, avoiding confusion. Use 'pmu_alias' for 'struct pmu_alias' variables. Co-developed-by: Jin Yao <yao.jin@linux.intel.com> Co-developed-by: Arnaldo Carvalho de Melo <acme@kernel.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.garry@huawei.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Riccardo Mancini <rickyman7@gmail.com> Link: http://lore.kernel.org/lkml/20210902065955.1299-2-yao.jin@linux.intel.com Signed-off-by: Jin Yao <yao.jin@linux.intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/arch')
-rw-r--r--tools/perf/arch/x86/util/pmu.c155
1 files changed, 154 insertions, 1 deletions
diff --git a/tools/perf/arch/x86/util/pmu.c b/tools/perf/arch/x86/util/pmu.c
index d48d608517fd..74d69db1ea99 100644
--- a/tools/perf/arch/x86/util/pmu.c
+++ b/tools/perf/arch/x86/util/pmu.c
@@ -1,12 +1,30 @@
// SPDX-License-Identifier: GPL-2.0
#include <string.h>
-
+#include <stdio.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <fcntl.h>
#include <linux/stddef.h>
#include <linux/perf_event.h>
+#include <linux/zalloc.h>
+#include <api/fs/fs.h>
+#include <errno.h>
#include "../../../util/intel-pt.h"
#include "../../../util/intel-bts.h"
#include "../../../util/pmu.h"
+#include "../../../util/fncache.h"
+
+#define TEMPLATE_ALIAS "%s/bus/event_source/devices/%s/alias"
+
+struct pmu_alias {
+ char *name;
+ char *alias;
+ struct list_head list;
+};
+
+static LIST_HEAD(pmu_alias_name_list);
+static bool cached_list;
struct perf_event_attr *perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
{
@@ -18,3 +36,138 @@ struct perf_event_attr *perf_pmu__get_default_config(struct perf_pmu *pmu __mayb
#endif
return NULL;
}
+
+static void pmu_alias__delete(struct pmu_alias *pmu_alias)
+{
+ if (!pmu_alias)
+ return;
+
+ zfree(&pmu_alias->name);
+ zfree(&pmu_alias->alias);
+ free(pmu_alias);
+}
+
+static struct pmu_alias *pmu_alias__new(char *name, char *alias)
+{
+ struct pmu_alias *pmu_alias = zalloc(sizeof(*pmu_alias));
+
+ if (pmu_alias) {
+ pmu_alias->name = strdup(name);
+ if (!pmu_alias->name)
+ goto out_delete;
+
+ pmu_alias->alias = strdup(alias);
+ if (!pmu_alias->alias)
+ goto out_delete;
+ }
+ return pmu_alias;
+
+out_delete:
+ pmu_alias__delete(pmu_alias);
+ return NULL;
+}
+
+static int setup_pmu_alias_list(void)
+{
+ char path[PATH_MAX];
+ DIR *dir;
+ struct dirent *dent;
+ const char *sysfs = sysfs__mountpoint();
+ struct pmu_alias *pmu_alias;
+ char buf[MAX_PMU_NAME_LEN];
+ FILE *file;
+ int ret = -ENOMEM;
+
+ if (!sysfs)
+ return -1;
+
+ snprintf(path, PATH_MAX,
+ "%s" EVENT_SOURCE_DEVICE_PATH, sysfs);
+
+ dir = opendir(path);
+ if (!dir)
+ return -errno;
+
+ while ((dent = readdir(dir))) {
+ if (!strcmp(dent->d_name, ".") ||
+ !strcmp(dent->d_name, ".."))
+ continue;
+
+ snprintf(path, PATH_MAX,
+ TEMPLATE_ALIAS, sysfs, dent->d_name);
+
+ if (!file_available(path))
+ continue;
+
+ file = fopen(path, "r");
+ if (!file)
+ continue;
+
+ if (!fgets(buf, sizeof(buf), file)) {
+ fclose(file);
+ continue;
+ }
+
+ fclose(file);
+
+ /* Remove the last '\n' */
+ buf[strlen(buf) - 1] = 0;
+
+ pmu_alias = pmu_alias__new(dent->d_name, buf);
+ if (!pmu_alias)
+ goto close_dir;
+
+ list_add_tail(&pmu_alias->list, &pmu_alias_name_list);
+ }
+
+ ret = 0;
+
+close_dir:
+ closedir(dir);
+ return ret;
+}
+
+static char *__pmu_find_real_name(const char *name)
+{
+ struct pmu_alias *pmu_alias;
+
+ list_for_each_entry(pmu_alias, &pmu_alias_name_list, list) {
+ if (!strcmp(name, pmu_alias->alias))
+ return pmu_alias->name;
+ }
+
+ return (char *)name;
+}
+
+char *pmu_find_real_name(const char *name)
+{
+ if (cached_list)
+ return __pmu_find_real_name(name);
+
+ setup_pmu_alias_list();
+ cached_list = true;
+
+ return __pmu_find_real_name(name);
+}
+
+static char *__pmu_find_alias_name(const char *name)
+{
+ struct pmu_alias *pmu_alias;
+
+ list_for_each_entry(pmu_alias, &pmu_alias_name_list, list) {
+ if (!strcmp(name, pmu_alias->name))
+ return pmu_alias->alias;
+ }
+ return NULL;
+}
+
+char *pmu_find_alias_name(const char *name)
+{
+ if (cached_list)
+ return __pmu_find_alias_name(name);
+
+ setup_pmu_alias_list();
+ cached_list = true;
+
+ return __pmu_find_alias_name(name);
+}