From: Zhengjun Xing <[email protected]>
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: acb65150a47c ("perf record: Support sample-read topdown metric group")
Signed-off-by: Zhengjun Xing <[email protected]>
Reviewed-by: Kan Liang <[email protected]>
---
tools/perf/arch/x86/util/evsel.c | 3 ++-
tools/perf/arch/x86/util/evsel.h | 7 +++++++
tools/perf/arch/x86/util/topdown.c | 21 ++++-----------------
3 files changed, 13 insertions(+), 18 deletions(-)
create mode 100644 tools/perf/arch/x86/util/evsel.h
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;
--
2.25.1
On Thu, Jun 2, 2022 at 8:35 AM <[email protected]> wrote:
>
> From: Zhengjun Xing <[email protected]>
>
> 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: acb65150a47c ("perf record: Support sample-read topdown metric group")
> Signed-off-by: Zhengjun Xing <[email protected]>
> Reviewed-by: Kan Liang <[email protected]>
Acked-by: Ian Rogers <[email protected]>
Thanks,
Ian
> ---
> tools/perf/arch/x86/util/evsel.c | 3 ++-
> tools/perf/arch/x86/util/evsel.h | 7 +++++++
> tools/perf/arch/x86/util/topdown.c | 21 ++++-----------------
> 3 files changed, 13 insertions(+), 18 deletions(-)
> create mode 100644 tools/perf/arch/x86/util/evsel.h
>
> 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;
> --
> 2.25.1
>