[tip:perf/urgent] perf pmu: Fix core PMU alias list for X86 platform

[tip-bot for Kan Liang]

Commit-ID:  292c34c10249c64a70def442f0d977bf9d466ed7
Gitweb: https://git.kernel.org/tip/292c34c10249c64a70def442f0d977bf9d466ed7
Author: Kan Liang 
AuthorDate: Tue, 24 Apr 2018 11:20:10 -0700
Committer:  Arnaldo Carvalho de Melo 
CommitDate: Tue, 24 Apr 2018 16:02:29 -0300

perf pmu: Fix core PMU alias list for X86 platform

When counting uncore event with alias, core event is mistakenly
involved, for example:

  perf stat --no-merge -e "unc_m_cas_count.all" -C0  sleep 1

  Performance counter stats for 'CPU(s) 0':

 0  unc_m_cas_count.all [uncore_imc_4]
 0  unc_m_cas_count.all [uncore_imc_2]
 0  unc_m_cas_count.all [uncore_imc_0]
   153,640  unc_m_cas_count.all [cpu]
 0  unc_m_cas_count.all [uncore_imc_5]
25,026  unc_m_cas_count.all [uncore_imc_3]
 0  unc_m_cas_count.all [uncore_imc_1]

   1.001447890 seconds time elapsed

The reason is that current implementation doesn't check PMU name of a
event when adding its alias into the alias list for core PMU. The
uncore event aliases are mistakenly added.

This bug was introduced in:
  commit 14b22ae028de ("perf pmu: Add helper function is_pmu_core to
  detect PMU CORE devices")

Checking the PMU name for all PMUs on X86 and other architectures except
ARM.
There is no behavior change for ARM.

Signed-off-by: Kan Liang 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Agustin Vega-Frias 
Cc: Andi Kleen 
Cc: Ganapatrao Kulkarni 
Cc: Jin Yao 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Shaokun Zhang 
Cc: Will Deacon 
Fixes: 14b22ae028de ("perf pmu: Add helper function is_pmu_core to detect PMU 
CORE devices")
Link: 
http://lkml.kernel.org/r/1524594014-79243-1-git-send-email-kan.li...@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
---
 tools/perf/util/pmu.c | 20 +++-
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index af4bedf4cf98..d2fb597c9a8c 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -539,9 +539,10 @@ static bool pmu_is_uncore(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.
+ *  platforms.
+ *  Looking for possible sysfs files to identify the arm core device.
  */
-static int is_pmu_core(const char *name)
+static int is_arm_pmu_core(const char *name)
 {
struct stat st;
char path[PATH_MAX];
@@ -550,12 +551,6 @@ static int is_pmu_core(const char *name)
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, ) == 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);
@@ -668,6 +663,7 @@ static void pmu_add_cpu_aliases(struct list_head *head, 
struct perf_pmu *pmu)
struct pmu_events_map *map;
struct pmu_event *pe;
const char *name = pmu->name;
+   const char *pname;
 
map = perf_pmu__find_map(pmu);
if (!map)
@@ -686,11 +682,9 @@ static void pmu_add_cpu_aliases(struct list_head *head, 
struct perf_pmu *pmu)
break;
}
 
-   if (!is_pmu_core(name)) {
-   /* check for uncore devices */
-   if (pe->pmu == NULL)
-   continue;
-   if (strncmp(pe->pmu, name, strlen(pe->pmu)))
+   if (!is_arm_pmu_core(name)) {
+   pname = pe->pmu ? pe->pmu : "cpu";
+   if (strncmp(pname, name, strlen(pname)))
continue;
}
 

[tip:perf/urgent] perf pmu: Fix core PMU alias list for X86 platform

[tip-bot for Kan Liang]

Commit-ID:  292c34c10249c64a70def442f0d977bf9d466ed7
Gitweb: https://git.kernel.org/tip/292c34c10249c64a70def442f0d977bf9d466ed7
Author: Kan Liang 
AuthorDate: Tue, 24 Apr 2018 11:20:10 -0700
Committer:  Arnaldo Carvalho de Melo 
CommitDate: Tue, 24 Apr 2018 16:02:29 -0300

perf pmu: Fix core PMU alias list for X86 platform

When counting uncore event with alias, core event is mistakenly
involved, for example:

  perf stat --no-merge -e "unc_m_cas_count.all" -C0  sleep 1

  Performance counter stats for 'CPU(s) 0':

 0  unc_m_cas_count.all [uncore_imc_4]
 0  unc_m_cas_count.all [uncore_imc_2]
 0  unc_m_cas_count.all [uncore_imc_0]
   153,640  unc_m_cas_count.all [cpu]
 0  unc_m_cas_count.all [uncore_imc_5]
25,026  unc_m_cas_count.all [uncore_imc_3]
 0  unc_m_cas_count.all [uncore_imc_1]

   1.001447890 seconds time elapsed

The reason is that current implementation doesn't check PMU name of a
event when adding its alias into the alias list for core PMU. The
uncore event aliases are mistakenly added.

This bug was introduced in:
  commit 14b22ae028de ("perf pmu: Add helper function is_pmu_core to
  detect PMU CORE devices")

Checking the PMU name for all PMUs on X86 and other architectures except
ARM.
There is no behavior change for ARM.

Signed-off-by: Kan Liang 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Agustin Vega-Frias 
Cc: Andi Kleen 
Cc: Ganapatrao Kulkarni 
Cc: Jin Yao 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Shaokun Zhang 
Cc: Will Deacon 
Fixes: 14b22ae028de ("perf pmu: Add helper function is_pmu_core to detect PMU 
CORE devices")
Link: 
http://lkml.kernel.org/r/1524594014-79243-1-git-send-email-kan.li...@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
---
 tools/perf/util/pmu.c | 20 +++-
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index af4bedf4cf98..d2fb597c9a8c 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -539,9 +539,10 @@ static bool pmu_is_uncore(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.
+ *  platforms.
+ *  Looking for possible sysfs files to identify the arm core device.
  */
-static int is_pmu_core(const char *name)
+static int is_arm_pmu_core(const char *name)
 {
struct stat st;
char path[PATH_MAX];
@@ -550,12 +551,6 @@ static int is_pmu_core(const char *name)
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, ) == 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);
@@ -668,6 +663,7 @@ static void pmu_add_cpu_aliases(struct list_head *head, 
struct perf_pmu *pmu)
struct pmu_events_map *map;
struct pmu_event *pe;
const char *name = pmu->name;
+   const char *pname;
 
map = perf_pmu__find_map(pmu);
if (!map)
@@ -686,11 +682,9 @@ static void pmu_add_cpu_aliases(struct list_head *head, 
struct perf_pmu *pmu)
break;
}
 
-   if (!is_pmu_core(name)) {
-   /* check for uncore devices */
-   if (pe->pmu == NULL)
-   continue;
-   if (strncmp(pe->pmu, name, strlen(pe->pmu)))
+   if (!is_arm_pmu_core(name)) {
+   pname = pe->pmu ? pe->pmu : "cpu";
+   if (strncmp(pname, name, strlen(pname)))
continue;
}