This is a note to let you know that I've just added the patch titled
perf record: Support sample-read topdown metric group for hybrid platforms
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-record-support-sample-read-topdown-metric-group.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1a7154b7290b871af464ba4e84cfe997678e1812
Author: Zhengjun Xing <zhengjun.xing@xxxxxxxxxxxxxxx>
Date: Thu Jun 2 23:36:03 2022 +0800
perf record: Support sample-read topdown metric group for hybrid platforms
[ Upstream commit 151e7d75036b4e2ac0f33730bc1a5b3ff424d9a7 ]
With the hardware TopDown metrics feature, the sample-read feature should
be supported for a TopDown group, e.g., sample a non-topdown event and read
a Topdown metric group. But the current perf record code errors are out.
For a TopDown metric group,the slots event must be the leader of the group,
but the leader slots event doesn't support sampling. To support sample-read
the TopDown metric group, uses the 2nd event of the group as the "leader"
for the purposes of sampling.
Only the platform with the TopDown metric feature supports sample-read the
topdown group. In commit acb65150a47c ("perf record: Support sample-read
topdown metric group"), it adds arch_topdown_sample_read() to indicate
whether the TopDown group supports sample-read, it should only work on the
non-hybrid systems, this patch extends the support for hybrid platforms.
Before:
# ./perf record -e "{cpu_core/slots/,cpu_core/cycles/,cpu_core/topdown-retiring/}:S" -a sleep 1
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cpu_core/topdown-retiring/).
/bin/dmesg | grep -i perf may provide additional information.
After:
# ./perf record -e "{cpu_core/slots/,cpu_core/cycles/,cpu_core/topdown-retiring/}:S" -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.238 MB perf.data (369 samples) ]
Fixes: acb65150a47c2bae ("perf record: Support sample-read topdown metric group")
Reviewed-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Signed-off-by: Zhengjun Xing <zhengjun.xing@xxxxxxxxxxxxxxx>
Acked-by: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220602153603.1884710-1-zhengjun.xing@xxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/perf/arch/x86/util/evsel.c b/tools/perf/arch/x86/util/evsel.c
index ff4561b7b600..3501399cef35 100644
--- a/tools/perf/arch/x86/util/evsel.c
+++ b/tools/perf/arch/x86/util/evsel.c
@@ -5,6 +5,7 @@
#include "util/env.h"
#include "util/pmu.h"
#include "linux/string.h"
+#include "evsel.h"
void arch_evsel__set_sample_weight(struct evsel *evsel)
{
@@ -32,7 +33,7 @@ void arch_evsel__fixup_new_cycles(struct perf_event_attr *attr)
}
/* Check whether the evsel's PMU supports the perf metrics */
-static bool evsel__sys_has_perf_metrics(const struct evsel *evsel)
+bool evsel__sys_has_perf_metrics(const struct evsel *evsel)
{
const char *pmu_name = evsel->pmu_name ? evsel->pmu_name : "cpu";
diff --git a/tools/perf/arch/x86/util/evsel.h b/tools/perf/arch/x86/util/evsel.h
new file mode 100644
index 000000000000..19ad1691374d
--- /dev/null
+++ b/tools/perf/arch/x86/util/evsel.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _EVSEL_H
+#define _EVSEL_H 1
+
+bool evsel__sys_has_perf_metrics(const struct evsel *evsel);
+
+#endif
diff --git a/tools/perf/arch/x86/util/topdown.c b/tools/perf/arch/x86/util/topdown.c
index f4d5422e9960..f81a7cfe4d63 100644
--- a/tools/perf/arch/x86/util/topdown.c
+++ b/tools/perf/arch/x86/util/topdown.c
@@ -4,6 +4,7 @@
#include "util/pmu.h"
#include "util/topdown.h"
#include "topdown.h"
+#include "evsel.h"
/* Check whether there is a PMU which supports the perf metrics. */
bool topdown_sys_has_perf_metrics(void)
@@ -55,33 +56,19 @@ void arch_topdown_group_warn(void)
#define TOPDOWN_SLOTS 0x0400
-static bool is_topdown_slots_event(struct evsel *counter)
-{
- if (!counter->pmu_name)
- return false;
-
- if (strcmp(counter->pmu_name, "cpu"))
- return false;
-
- if (counter->core.attr.config == TOPDOWN_SLOTS)
- return true;
-
- return false;
-}
-
/*
* Check whether a topdown group supports sample-read.
*
- * Only Topdown metic supports sample-read. The slots
+ * Only Topdown metric supports sample-read. The slots
* event must be the leader of the topdown group.
*/
bool arch_topdown_sample_read(struct evsel *leader)
{
- if (!pmu_have_event("cpu", "slots"))
+ if (!evsel__sys_has_perf_metrics(leader))
return false;
- if (is_topdown_slots_event(leader))
+ if (leader->core.attr.config == TOPDOWN_SLOTS)
return true;
return false;
