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From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Clark Williams <williams@redhat.com>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	Kan Liang <kan.liang@linux.intel.com>,
	Agustin Vega-Frias <agustinv@codeaurora.org>,
	Andi Kleen <ak@linux.intel.com>,
	Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>,
	Jin Yao <yao.jin@linux.intel.com>, Jiri Olsa <jolsa@redhat.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Shaokun Zhang <zhangshaokun@hisilicon.com>,
	Will Deacon <will.deacon@arm.com>,
	Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: [PATCH 09/12] perf pmu: Fix core PMU alias list for X86 platform
Date: Wed, 25 Apr 2018 13:00:05 -0300	[thread overview]
Message-ID: <20180425160008.3407-10-acme@kernel.org> (raw)
In-Reply-To: <20180425160008.3407-1-acme@kernel.org>

From: Kan Liang <kan.liang@linux.intel.com>

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 <kan.liang@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Agustin Vega-Frias <agustinv@codeaurora.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Will Deacon <will.deacon@arm.com>
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.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 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, &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);
@@ -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;
 		}
 
-- 
2.14.3

  parent reply	other threads:[~2018-04-25 16:00 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-25 15:59 [GIT PULL 00/12] perf/urgent fixes Arnaldo Carvalho de Melo
2018-04-25 15:59 ` [PATCH 01/12] perf machine: Set main kernel end address properly Arnaldo Carvalho de Melo
2018-04-25 15:59 ` [PATCH 02/12] perf list: Remove s390 specific strcmp_cpuid_cmp function Arnaldo Carvalho de Melo
2018-04-25 15:59 ` [PATCH 03/12] perf test: Adapt test case record+probe_libc_inet_pton.sh for s390 Arnaldo Carvalho de Melo
2018-04-25 16:00 ` [PATCH 04/12] perf stat: Keep the / modifier separator in fallback Arnaldo Carvalho de Melo
2018-04-25 16:00 ` [PATCH 05/12] perf pmu: Fix pmu events parsing rule Arnaldo Carvalho de Melo
2018-05-03  8:25   ` Adrian Hunter
2018-05-03 10:37     ` Jiri Olsa
2018-05-03 11:38       ` Adrian Hunter
2018-05-03 11:47         ` Jiri Olsa
2018-05-04 16:02         ` Jiri Olsa
2018-05-06  3:43           ` Andi Kleen
2018-05-06 14:28             ` [PATCH] perf tools: Fix parser for empty pmu terms case Jiri Olsa
2018-05-06 16:34               ` Liang, Kan
2018-05-07  7:21               ` Adrian Hunter
2018-05-07  8:12                 ` Jiri Olsa
2018-05-07 15:04                   ` Arnaldo Carvalho de Melo
2018-05-07 18:37             ` [PATCH 05/12] perf pmu: Fix pmu events parsing rule Arnaldo Carvalho de Melo
2018-05-07 19:16               ` Jiri Olsa
2018-05-07 19:26                 ` Arnaldo Carvalho de Melo
2018-05-07 19:24               ` Arnaldo Carvalho de Melo
2018-05-07 19:42                 ` Jiri Olsa
2018-04-25 16:00 ` [PATCH 06/12] perf evsel: Disable write_backward for leader sampling group events Arnaldo Carvalho de Melo
2018-04-25 16:00 ` [PATCH 07/12] perf mem: Document incorrect and missing options Arnaldo Carvalho de Melo
2018-04-25 16:00 ` [PATCH 08/12] perf record: Fix s390 undefined record__auxtrace_init() return value Arnaldo Carvalho de Melo
2018-04-25 16:00 ` Arnaldo Carvalho de Melo [this message]
2018-04-25 16:00 ` [PATCH 10/12] perf stat: Print out hint for mixed PMU group error Arnaldo Carvalho de Melo
2018-04-25 16:00 ` [PATCH 11/12] perf evsel: Only fall back group read for leader Arnaldo Carvalho de Melo
2018-04-25 16:00 ` [PATCH 12/12] perf stat: Fix duplicate PMU name for interval print Arnaldo Carvalho de Melo
2018-04-26  5:33 ` [GIT PULL 00/12] perf/urgent fixes Ingo Molnar

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