[PATCH v1 1/2] perf bpf_counter: Move header declarations into C code

[PATCH v1 1/2] perf bpf_counter: Move header declarations into C code

[Ian Rogers]

Reduce the API surface that is in bpf_counter.h, this helps compiler
analysis like unused static function, makes it easier to set a
breakpoint and just makes it easier to see the code is self
contained. When code is shared between BPF C code, put it inside
HAVE_BPF_SKEL. Move transitively found #includes into appropriate C
files.
No functional change.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/bpf_counter.c        | 62 ++++++++++++++++++++++-
 tools/perf/util/bpf_counter.h        | 74 +++-------------------------
 tools/perf/util/bpf_counter_cgroup.c |  1 +
 tools/perf/util/bpf_ftrace.c         |  1 +
 tools/perf/util/bpf_off_cpu.c        |  1 +
 5 files changed, 69 insertions(+), 70 deletions(-)

diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
index 73fcafbffc6a..1c6cb5ea077e 100644
--- a/tools/perf/util/bpf_counter.c
+++ b/tools/perf/util/bpf_counter.c
@@ -6,10 +6,14 @@
 #include <limits.h>
 #include <unistd.h>
 #include <sys/file.h>
+#include <sys/resource.h>
 #include <sys/time.h>
 #include <linux/err.h>
+#include <linux/list.h>
 #include <linux/zalloc.h>
 #include <api/fs/fs.h>
+#include <bpf/bpf.h>
+#include <bpf/btf.h>
 #include <perf/bpf_perf.h>
 
 #include "bpf_counter.h"
@@ -28,13 +32,67 @@
 #include "bpf_skel/bperf_leader.skel.h"
 #include "bpf_skel/bperf_follower.skel.h"
 
+struct bpf_counter {
+	void *skel;
+	struct list_head list;
+};
+
 #define ATTR_MAP_SIZE 16
 
-static inline void *u64_to_ptr(__u64 ptr)
+static void *u64_to_ptr(__u64 ptr)
 {
 	return (void *)(unsigned long)ptr;
 }
 
+
+void set_max_rlimit(void)
+{
+	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
+
+	setrlimit(RLIMIT_MEMLOCK, &rinf);
+}
+
+static __u32 bpf_link_get_id(int fd)
+{
+	struct bpf_link_info link_info = { .id = 0, };
+	__u32 link_info_len = sizeof(link_info);
+
+	bpf_obj_get_info_by_fd(fd, &link_info, &link_info_len);
+	return link_info.id;
+}
+
+static __u32 bpf_link_get_prog_id(int fd)
+{
+	struct bpf_link_info link_info = { .id = 0, };
+	__u32 link_info_len = sizeof(link_info);
+
+	bpf_obj_get_info_by_fd(fd, &link_info, &link_info_len);
+	return link_info.prog_id;
+}
+
+static __u32 bpf_map_get_id(int fd)
+{
+	struct bpf_map_info map_info = { .id = 0, };
+	__u32 map_info_len = sizeof(map_info);
+
+	bpf_obj_get_info_by_fd(fd, &map_info, &map_info_len);
+	return map_info.id;
+}
+
+/* trigger the leader program on a cpu */
+int bperf_trigger_reading(int prog_fd, int cpu)
+{
+	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
+			    .ctx_in = NULL,
+			    .ctx_size_in = 0,
+			    .flags = BPF_F_TEST_RUN_ON_CPU,
+			    .cpu = cpu,
+			    .retval = 0,
+		);
+
+	return bpf_prog_test_run_opts(prog_fd, &opts);
+}
+
 static struct bpf_counter *bpf_counter_alloc(void)
 {
 	struct bpf_counter *counter;
@@ -785,7 +843,7 @@ struct bpf_counter_ops bperf_ops = {
 
 extern struct bpf_counter_ops bperf_cgrp_ops;
 
-static inline bool bpf_counter_skip(struct evsel *evsel)
+static bool bpf_counter_skip(struct evsel *evsel)
 {
 	return evsel->bpf_counter_ops == NULL;
 }
diff --git a/tools/perf/util/bpf_counter.h b/tools/perf/util/bpf_counter.h
index c6d21c07b14c..658d8e7d507e 100644
--- a/tools/perf/util/bpf_counter.h
+++ b/tools/perf/util/bpf_counter.h
@@ -2,18 +2,10 @@
 #ifndef __PERF_BPF_COUNTER_H
 #define __PERF_BPF_COUNTER_H 1
 
-#include <linux/list.h>
-#include <sys/resource.h>
-
-#ifdef HAVE_LIBBPF_SUPPORT
-#include <bpf/bpf.h>
-#include <bpf/btf.h>
-#include <bpf/libbpf.h>
-#endif
-
 struct evsel;
 struct target;
-struct bpf_counter;
+
+#ifdef HAVE_BPF_SKEL
 
 typedef int (*bpf_counter_evsel_op)(struct evsel *evsel);
 typedef int (*bpf_counter_evsel_target_op)(struct evsel *evsel,
@@ -22,6 +14,7 @@ typedef int (*bpf_counter_evsel_install_pe_op)(struct evsel *evsel,
 					       int cpu_map_idx,
 					       int fd);
 
+/* Shared ops between bpf_counter, bpf_counter_cgroup, etc. */
 struct bpf_counter_ops {
 	bpf_counter_evsel_target_op load;
 	bpf_counter_evsel_op enable;
@@ -31,13 +24,6 @@ struct bpf_counter_ops {
 	bpf_counter_evsel_install_pe_op install_pe;
 };
 
-struct bpf_counter {
-	void *skel;
-	struct list_head list;
-};
-
-#ifdef HAVE_BPF_SKEL
-
 int bpf_counter__load(struct evsel *evsel, struct target *target);
 int bpf_counter__enable(struct evsel *evsel);
 int bpf_counter__disable(struct evsel *evsel);
@@ -45,6 +31,9 @@ int bpf_counter__read(struct evsel *evsel);
 void bpf_counter__destroy(struct evsel *evsel);
 int bpf_counter__install_pe(struct evsel *evsel, int cpu_map_idx, int fd);
 
+int bperf_trigger_reading(int prog_fd, int cpu);
+void set_max_rlimit(void);
+
 #else /* HAVE_BPF_SKEL */
 
 #include <linux/err.h>
@@ -83,55 +72,4 @@ static inline int bpf_counter__install_pe(struct evsel *evsel __maybe_unused,
 
 #endif /* HAVE_BPF_SKEL */
 
-static inline void set_max_rlimit(void)
-{
-	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
-
-	setrlimit(RLIMIT_MEMLOCK, &rinf);
-}
-
-#ifdef HAVE_BPF_SKEL
-
-static inline __u32 bpf_link_get_id(int fd)
-{
-	struct bpf_link_info link_info = { .id = 0, };
-	__u32 link_info_len = sizeof(link_info);
-
-	bpf_obj_get_info_by_fd(fd, &link_info, &link_info_len);
-	return link_info.id;
-}
-
-static inline __u32 bpf_link_get_prog_id(int fd)
-{
-	struct bpf_link_info link_info = { .id = 0, };
-	__u32 link_info_len = sizeof(link_info);
-
-	bpf_obj_get_info_by_fd(fd, &link_info, &link_info_len);
-	return link_info.prog_id;
-}
-
-static inline __u32 bpf_map_get_id(int fd)
-{
-	struct bpf_map_info map_info = { .id = 0, };
-	__u32 map_info_len = sizeof(map_info);
-
-	bpf_obj_get_info_by_fd(fd, &map_info, &map_info_len);
-	return map_info.id;
-}
-
-/* trigger the leader program on a cpu */
-static inline int bperf_trigger_reading(int prog_fd, int cpu)
-{
-	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
-			    .ctx_in = NULL,
-			    .ctx_size_in = 0,
-			    .flags = BPF_F_TEST_RUN_ON_CPU,
-			    .cpu = cpu,
-			    .retval = 0,
-		);
-
-	return bpf_prog_test_run_opts(prog_fd, &opts);
-}
-#endif /* HAVE_BPF_SKEL */
-
 #endif /* __PERF_BPF_COUNTER_H */
diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c
index 6ff42619de12..ed6a29b106b4 100644
--- a/tools/perf/util/bpf_counter_cgroup.c
+++ b/tools/perf/util/bpf_counter_cgroup.c
@@ -13,6 +13,7 @@
 #include <linux/zalloc.h>
 #include <linux/perf_event.h>
 #include <api/fs/fs.h>
+#include <bpf/bpf.h>
 #include <perf/bpf_perf.h>
 
 #include "affinity.h"
diff --git a/tools/perf/util/bpf_ftrace.c b/tools/perf/util/bpf_ftrace.c
index 0cb02412043c..e61a3b20be0a 100644
--- a/tools/perf/util/bpf_ftrace.c
+++ b/tools/perf/util/bpf_ftrace.c
@@ -3,6 +3,7 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+#include <bpf/bpf.h>
 #include <linux/err.h>
 
 #include "util/ftrace.h"
diff --git a/tools/perf/util/bpf_off_cpu.c b/tools/perf/util/bpf_off_cpu.c
index c367fefe6ecb..88e0660c4bff 100644
--- a/tools/perf/util/bpf_off_cpu.c
+++ b/tools/perf/util/bpf_off_cpu.c
@@ -13,6 +13,7 @@
 #include "util/cgroup.h"
 #include "util/strlist.h"
 #include <bpf/bpf.h>
+#include <bpf/btf.h>
 #include <internal/xyarray.h>
 #include <linux/time64.h>
 
-- 
2.51.0.618.g983fd99d29-goog

[PATCH v1 2/2] perf bpf_counter: Fix handling of cpumap fixing hybrid

[Ian Rogers]

Don't open evsels on all CPUs, open them just on the CPUs they
support. This avoids opening say an e-core event on a p-core and
getting a failure - achieve this by getting rid of the "all_cpu_map".

In install_pe functions don't use the cpu_map_idx as a CPU number,
translate the cpu_map_idx, which is a dense index into the cpu_map
skipping holes at the beginning, to a proper CPU number.

Before:
```
$ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1

 Performance counter stats for 'system wide':

   <not supported>      cpu_atom/cycles/
       566,270,672      cpu_core/cycles/
   <not supported>      cpu_atom/instructions/
       572,792,836      cpu_core/instructions/           #    1.01  insn per cycle

       1.001595384 seconds time elapsed
```

After:
```
$ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1

 Performance counter stats for 'system wide':

       443,299,201      cpu_atom/cycles/
     1,233,919,737      cpu_core/cycles/
       213,634,112      cpu_atom/instructions/           #    0.48  insn per cycle
     2,758,965,527      cpu_core/instructions/           #    2.24  insn per cycle

       1.001699485 seconds time elapsed
```

Fixes: 7fac83aaf2ee ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF")
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/bpf_counter.c        | 26 ++++++++++----------------
 tools/perf/util/bpf_counter_cgroup.c |  3 ++-
 2 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
index 1c6cb5ea077e..ca5d01b9017d 100644
--- a/tools/perf/util/bpf_counter.c
+++ b/tools/perf/util/bpf_counter.c
@@ -336,6 +336,7 @@ static int bpf_program_profiler__install_pe(struct evsel *evsel, int cpu_map_idx
 {
 	struct bpf_prog_profiler_bpf *skel;
 	struct bpf_counter *counter;
+	int cpu = perf_cpu_map__cpu(evsel->core.cpus, cpu_map_idx).cpu;
 	int ret;
 
 	list_for_each_entry(counter, &evsel->bpf_counter_list, list) {
@@ -343,7 +344,7 @@ static int bpf_program_profiler__install_pe(struct evsel *evsel, int cpu_map_idx
 		assert(skel != NULL);
 
 		ret = bpf_map_update_elem(bpf_map__fd(skel->maps.events),
-					  &cpu_map_idx, &fd, BPF_ANY);
+					  &cpu, &fd, BPF_ANY);
 		if (ret)
 			return ret;
 	}
@@ -451,7 +452,6 @@ static int bperf_check_target(struct evsel *evsel,
 	return 0;
 }
 
-static	struct perf_cpu_map *all_cpu_map;
 static __u32 filter_entry_cnt;
 
 static int bperf_reload_leader_program(struct evsel *evsel, int attr_map_fd,
@@ -495,7 +495,7 @@ static int bperf_reload_leader_program(struct evsel *evsel, int attr_map_fd,
 	 * following evsel__open_per_cpu call
 	 */
 	evsel->leader_skel = skel;
-	evsel__open_per_cpu(evsel, all_cpu_map, -1);
+	evsel__open(evsel, evsel->core.cpus, evsel->core.threads);
 
 out:
 	bperf_leader_bpf__destroy(skel);
@@ -533,12 +533,6 @@ static int bperf__load(struct evsel *evsel, struct target *target)
 	if (bperf_check_target(evsel, target, &filter_type, &filter_entry_cnt))
 		return -1;
 
-	if (!all_cpu_map) {
-		all_cpu_map = perf_cpu_map__new_online_cpus();
-		if (!all_cpu_map)
-			return -1;
-	}
-
 	evsel->bperf_leader_prog_fd = -1;
 	evsel->bperf_leader_link_fd = -1;
 
@@ -656,9 +650,10 @@ static int bperf__load(struct evsel *evsel, struct target *target)
 static int bperf__install_pe(struct evsel *evsel, int cpu_map_idx, int fd)
 {
 	struct bperf_leader_bpf *skel = evsel->leader_skel;
+	int cpu = perf_cpu_map__cpu(evsel->core.cpus, cpu_map_idx).cpu;
 
 	return bpf_map_update_elem(bpf_map__fd(skel->maps.events),
-				   &cpu_map_idx, &fd, BPF_ANY);
+				   &cpu, &fd, BPF_ANY);
 }
 
 /*
@@ -667,13 +662,12 @@ static int bperf__install_pe(struct evsel *evsel, int cpu_map_idx, int fd)
  */
 static int bperf_sync_counters(struct evsel *evsel)
 {
-	int num_cpu, i, cpu;
+	struct perf_cpu cpu;
+	int idx;
+
+	perf_cpu_map__for_each_cpu(cpu, idx, evsel->core.cpus)
+		bperf_trigger_reading(evsel->bperf_leader_prog_fd, cpu.cpu);
 
-	num_cpu = perf_cpu_map__nr(all_cpu_map);
-	for (i = 0; i < num_cpu; i++) {
-		cpu = perf_cpu_map__cpu(all_cpu_map, i).cpu;
-		bperf_trigger_reading(evsel->bperf_leader_prog_fd, cpu);
-	}
 	return 0;
 }
 
diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c
index ed6a29b106b4..690be3ce3e11 100644
--- a/tools/perf/util/bpf_counter_cgroup.c
+++ b/tools/perf/util/bpf_counter_cgroup.c
@@ -186,7 +186,8 @@ static int bperf_cgrp__load(struct evsel *evsel,
 }
 
 static int bperf_cgrp__install_pe(struct evsel *evsel __maybe_unused,
-				  int cpu __maybe_unused, int fd __maybe_unused)
+				  int cpu_map_idx __maybe_unused,
+				  int fd __maybe_unused)
 {
 	/* nothing to do */
 	return 0;
-- 
2.51.0.618.g983fd99d29-goog

Re: [PATCH v1 2/2] perf bpf_counter: Fix handling of cpumap fixing hybrid

[Ian Rogers]

On Wed, Oct 1, 2025 at 11:12 AM Ian Rogers <irogers@google.com> wrote:
>
> Don't open evsels on all CPUs, open them just on the CPUs they
> support. This avoids opening say an e-core event on a p-core and
> getting a failure - achieve this by getting rid of the "all_cpu_map".
>
> In install_pe functions don't use the cpu_map_idx as a CPU number,
> translate the cpu_map_idx, which is a dense index into the cpu_map
> skipping holes at the beginning, to a proper CPU number.
>
> Before:
> ```
> $ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
>
>  Performance counter stats for 'system wide':
>
>    <not supported>      cpu_atom/cycles/
>        566,270,672      cpu_core/cycles/
>    <not supported>      cpu_atom/instructions/
>        572,792,836      cpu_core/instructions/           #    1.01  insn per cycle
>
>        1.001595384 seconds time elapsed
> ```
>
> After:
> ```
> $ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
>
>  Performance counter stats for 'system wide':
>
>        443,299,201      cpu_atom/cycles/
>      1,233,919,737      cpu_core/cycles/
>        213,634,112      cpu_atom/instructions/           #    0.48  insn per cycle
>      2,758,965,527      cpu_core/instructions/           #    2.24  insn per cycle
>
>        1.001699485 seconds time elapsed
> ```
>
> Fixes: 7fac83aaf2ee ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF")
> Signed-off-by: Ian Rogers <irogers@google.com>

+Thomas Falcon

I think it'd be nice to get this quite major fix for
--bpf-counters/bperf for hybrid architectures into v6.18 and stable
builds. Thomas would it be possible for you to give a Tested-by tag
using the reproduction in the commit message?

Thanks,
Ian

> ---
>  tools/perf/util/bpf_counter.c        | 26 ++++++++++----------------
>  tools/perf/util/bpf_counter_cgroup.c |  3 ++-
>  2 files changed, 12 insertions(+), 17 deletions(-)
>
> diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
> index 1c6cb5ea077e..ca5d01b9017d 100644
> --- a/tools/perf/util/bpf_counter.c
> +++ b/tools/perf/util/bpf_counter.c
> @@ -336,6 +336,7 @@ static int bpf_program_profiler__install_pe(struct evsel *evsel, int cpu_map_idx
>  {
>         struct bpf_prog_profiler_bpf *skel;
>         struct bpf_counter *counter;
> +       int cpu = perf_cpu_map__cpu(evsel->core.cpus, cpu_map_idx).cpu;
>         int ret;
>
>         list_for_each_entry(counter, &evsel->bpf_counter_list, list) {
> @@ -343,7 +344,7 @@ static int bpf_program_profiler__install_pe(struct evsel *evsel, int cpu_map_idx
>                 assert(skel != NULL);
>
>                 ret = bpf_map_update_elem(bpf_map__fd(skel->maps.events),
> -                                         &cpu_map_idx, &fd, BPF_ANY);
> +                                         &cpu, &fd, BPF_ANY);
>                 if (ret)
>                         return ret;
>         }
> @@ -451,7 +452,6 @@ static int bperf_check_target(struct evsel *evsel,
>         return 0;
>  }
>
> -static struct perf_cpu_map *all_cpu_map;
>  static __u32 filter_entry_cnt;
>
>  static int bperf_reload_leader_program(struct evsel *evsel, int attr_map_fd,
> @@ -495,7 +495,7 @@ static int bperf_reload_leader_program(struct evsel *evsel, int attr_map_fd,
>          * following evsel__open_per_cpu call
>          */
>         evsel->leader_skel = skel;
> -       evsel__open_per_cpu(evsel, all_cpu_map, -1);
> +       evsel__open(evsel, evsel->core.cpus, evsel->core.threads);
>
>  out:
>         bperf_leader_bpf__destroy(skel);
> @@ -533,12 +533,6 @@ static int bperf__load(struct evsel *evsel, struct target *target)
>         if (bperf_check_target(evsel, target, &filter_type, &filter_entry_cnt))
>                 return -1;
>
> -       if (!all_cpu_map) {
> -               all_cpu_map = perf_cpu_map__new_online_cpus();
> -               if (!all_cpu_map)
> -                       return -1;
> -       }
> -
>         evsel->bperf_leader_prog_fd = -1;
>         evsel->bperf_leader_link_fd = -1;
>
> @@ -656,9 +650,10 @@ static int bperf__load(struct evsel *evsel, struct target *target)
>  static int bperf__install_pe(struct evsel *evsel, int cpu_map_idx, int fd)
>  {
>         struct bperf_leader_bpf *skel = evsel->leader_skel;
> +       int cpu = perf_cpu_map__cpu(evsel->core.cpus, cpu_map_idx).cpu;
>
>         return bpf_map_update_elem(bpf_map__fd(skel->maps.events),
> -                                  &cpu_map_idx, &fd, BPF_ANY);
> +                                  &cpu, &fd, BPF_ANY);
>  }
>
>  /*
> @@ -667,13 +662,12 @@ static int bperf__install_pe(struct evsel *evsel, int cpu_map_idx, int fd)
>   */
>  static int bperf_sync_counters(struct evsel *evsel)
>  {
> -       int num_cpu, i, cpu;
> +       struct perf_cpu cpu;
> +       int idx;
> +
> +       perf_cpu_map__for_each_cpu(cpu, idx, evsel->core.cpus)
> +               bperf_trigger_reading(evsel->bperf_leader_prog_fd, cpu.cpu);
>
> -       num_cpu = perf_cpu_map__nr(all_cpu_map);
> -       for (i = 0; i < num_cpu; i++) {
> -               cpu = perf_cpu_map__cpu(all_cpu_map, i).cpu;
> -               bperf_trigger_reading(evsel->bperf_leader_prog_fd, cpu);
> -       }
>         return 0;
>  }
>
> diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c
> index ed6a29b106b4..690be3ce3e11 100644
> --- a/tools/perf/util/bpf_counter_cgroup.c
> +++ b/tools/perf/util/bpf_counter_cgroup.c
> @@ -186,7 +186,8 @@ static int bperf_cgrp__load(struct evsel *evsel,
>  }
>
>  static int bperf_cgrp__install_pe(struct evsel *evsel __maybe_unused,
> -                                 int cpu __maybe_unused, int fd __maybe_unused)
> +                                 int cpu_map_idx __maybe_unused,
> +                                 int fd __maybe_unused)
>  {
>         /* nothing to do */
>         return 0;
> --
> 2.51.0.618.g983fd99d29-goog
>

Re: [PATCH v1 2/2] perf bpf_counter: Fix handling of cpumap fixing hybrid

[Arnaldo Carvalho de Melo]

On Mon, Oct 06, 2025 at 09:18:22AM -0700, Ian Rogers wrote:
> On Wed, Oct 1, 2025 at 11:12 AM Ian Rogers <irogers@google.com> wrote:
> >
> > Don't open evsels on all CPUs, open them just on the CPUs they
> > support. This avoids opening say an e-core event on a p-core and
> > getting a failure - achieve this by getting rid of the "all_cpu_map".
> >
> > In install_pe functions don't use the cpu_map_idx as a CPU number,
> > translate the cpu_map_idx, which is a dense index into the cpu_map
> > skipping holes at the beginning, to a proper CPU number.
> >
> > Before:
> > ```
> > $ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
> >
> >  Performance counter stats for 'system wide':
> >
> >    <not supported>      cpu_atom/cycles/
> >        566,270,672      cpu_core/cycles/
> >    <not supported>      cpu_atom/instructions/
> >        572,792,836      cpu_core/instructions/           #    1.01  insn per cycle
> >
> >        1.001595384 seconds time elapsed
> > ```
> >
> > After:
> > ```
> > $ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
> >
> >  Performance counter stats for 'system wide':
> >
> >        443,299,201      cpu_atom/cycles/
> >      1,233,919,737      cpu_core/cycles/
> >        213,634,112      cpu_atom/instructions/           #    0.48  insn per cycle
> >      2,758,965,527      cpu_core/instructions/           #    2.24  insn per cycle
> >
> >        1.001699485 seconds time elapsed
> > ```
> >
> > Fixes: 7fac83aaf2ee ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF")
> > Signed-off-by: Ian Rogers <irogers@google.com>
> 
> +Thomas Falcon
> 
> I think it'd be nice to get this quite major fix for
> --bpf-counters/bperf for hybrid architectures into v6.18 and stable
> builds. Thomas would it be possible for you to give a Tested-by tag
> using the reproduction in the commit message?

Its even already in linux-next:

⬢ [acme@toolbx perf-tools-next]$ git log -5 --oneline linux-next/master tools/perf/util/bpf_counter.c
b91917c0c6fa6df9 perf bpf_counter: Fix handling of cpumap fixing hybrid
8c519a825b4add85 perf bpf_counter: Move header declarations into C code
07dc3a6de33098b0 perf stat: Support inherit events during fork() for bperf
effe957c6bb70cac libperf cpumap: Replace usage of perf_cpu_map__new(NULL) with perf_cpu_map__new_online_cpus()
b84b3f47921568a8 perf bpf_counter: Fix a few memory leaks
⬢ [acme@toolbx perf-tools-next]$

Re: [PATCH v1 2/2] perf bpf_counter: Fix handling of cpumap fixing hybrid

[Falcon, Thomas]

On Mon, 2025-10-06 at 09:18 -0700, Ian Rogers wrote:
> On Wed, Oct 1, 2025 at 11:12 AM Ian Rogers <irogers@google.com>
> wrote:
> > 
> > Don't open evsels on all CPUs, open them just on the CPUs they
> > support. This avoids opening say an e-core event on a p-core and
> > getting a failure - achieve this by getting rid of the
> > "all_cpu_map".
> > 
> > In install_pe functions don't use the cpu_map_idx as a CPU number,
> > translate the cpu_map_idx, which is a dense index into the cpu_map
> > skipping holes at the beginning, to a proper CPU number.
> > 
> > Before:
> > ```
> > $ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
> > 
> >  Performance counter stats for 'system wide':
> > 
> >    <not supported>      cpu_atom/cycles/
> >        566,270,672      cpu_core/cycles/
> >    <not supported>      cpu_atom/instructions/
> >        572,792,836      cpu_core/instructions/           #    1.01 
> > insn per cycle
> > 
> >        1.001595384 seconds time elapsed
> > ```
> > 
> > After:
> > ```
> > $ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
> > 
> >  Performance counter stats for 'system wide':
> > 
> >        443,299,201      cpu_atom/cycles/
> >      1,233,919,737      cpu_core/cycles/
> >        213,634,112      cpu_atom/instructions/           #    0.48 
> > insn per cycle
> >      2,758,965,527      cpu_core/instructions/           #    2.24 
> > insn per cycle
> > 
> >        1.001699485 seconds time elapsed
> > ```
> > 
> > Fixes: 7fac83aaf2ee ("perf stat: Introduce 'bperf' to share
> > hardware PMCs with BPF")
> > Signed-off-by: Ian Rogers <irogers@google.com>
> 
> +Thomas Falcon
> 
> I think it'd be nice to get this quite major fix for
> --bpf-counters/bperf for hybrid architectures into v6.18 and stable
> builds. Thomas would it be possible for you to give a Tested-by tag
> using the reproduction in the commit message?
> 
> Thanks,
> Ian
> 

Sorry for missing this. Here's my reproduction on an alder lake

sudo ./perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
...

 Performance counter stats for 'system wide':

       364,715,896      cpu_atom/cycles/                              
       946,331,957      cpu_core/cycles/                              
       169,842,929      cpu_atom/instructions/           #    0.47 
insn per cycle            
     1,338,720,324      cpu_core/instructions/           #    1.41 
insn per cycle            

       1.001667769 seconds time elapsed

It looks like it's in perf-tools-next already but have my tested by for
what it's worth.

Tested-by: Thomas Falcon <thomas.falcon@intel.com>


> > ---
> >  tools/perf/util/bpf_counter.c        | 26 ++++++++++--------------
> > --
> >  tools/perf/util/bpf_counter_cgroup.c |  3 ++-
> >  2 files changed, 12 insertions(+), 17 deletions(-)
> > 
> > diff --git a/tools/perf/util/bpf_counter.c
> > b/tools/perf/util/bpf_counter.c
> > index 1c6cb5ea077e..ca5d01b9017d 100644
> > --- a/tools/perf/util/bpf_counter.c
> > +++ b/tools/perf/util/bpf_counter.c
> > @@ -336,6 +336,7 @@ static int
> > bpf_program_profiler__install_pe(struct evsel *evsel, int
> > cpu_map_idx
> >  {
> >         struct bpf_prog_profiler_bpf *skel;
> >         struct bpf_counter *counter;
> > +       int cpu = perf_cpu_map__cpu(evsel->core.cpus,
> > cpu_map_idx).cpu;
> >         int ret;
> > 
> >         list_for_each_entry(counter, &evsel->bpf_counter_list,
> > list) {
> > @@ -343,7 +344,7 @@ static int
> > bpf_program_profiler__install_pe(struct evsel *evsel, int
> > cpu_map_idx
> >                 assert(skel != NULL);
> > 
> >                 ret = bpf_map_update_elem(bpf_map__fd(skel-
> > >maps.events),
> > -                                         &cpu_map_idx, &fd,
> > BPF_ANY);
> > +                                         &cpu, &fd, BPF_ANY);
> >                 if (ret)
> >                         return ret;
> >         }
> > @@ -451,7 +452,6 @@ static int bperf_check_target(struct evsel
> > *evsel,
> >         return 0;
> >  }
> > 
> > -static struct perf_cpu_map *all_cpu_map;
> >  static __u32 filter_entry_cnt;
> > 
> >  static int bperf_reload_leader_program(struct evsel *evsel, int
> > attr_map_fd,
> > @@ -495,7 +495,7 @@ static int bperf_reload_leader_program(struct
> > evsel *evsel, int attr_map_fd,
> >          * following evsel__open_per_cpu call
> >          */
> >         evsel->leader_skel = skel;
> > -       evsel__open_per_cpu(evsel, all_cpu_map, -1);
> > +       evsel__open(evsel, evsel->core.cpus, evsel->core.threads);
> > 
> >  out:
> >         bperf_leader_bpf__destroy(skel);
> > @@ -533,12 +533,6 @@ static int bperf__load(struct evsel *evsel,
> > struct target *target)
> >         if (bperf_check_target(evsel, target, &filter_type,
> > &filter_entry_cnt))
> >                 return -1;
> > 
> > -       if (!all_cpu_map) {
> > -               all_cpu_map = perf_cpu_map__new_online_cpus();
> > -               if (!all_cpu_map)
> > -                       return -1;
> > -       }
> > -
> >         evsel->bperf_leader_prog_fd = -1;
> >         evsel->bperf_leader_link_fd = -1;
> > 
> > @@ -656,9 +650,10 @@ static int bperf__load(struct evsel *evsel,
> > struct target *target)
> >  static int bperf__install_pe(struct evsel *evsel, int cpu_map_idx,
> > int fd)
> >  {
> >         struct bperf_leader_bpf *skel = evsel->leader_skel;
> > +       int cpu = perf_cpu_map__cpu(evsel->core.cpus,
> > cpu_map_idx).cpu;
> > 
> >         return bpf_map_update_elem(bpf_map__fd(skel->maps.events),
> > -                                  &cpu_map_idx, &fd, BPF_ANY);
> > +                                  &cpu, &fd, BPF_ANY);
> >  }
> > 
> >  /*
> > @@ -667,13 +662,12 @@ static int bperf__install_pe(struct evsel
> > *evsel, int cpu_map_idx, int fd)
> >   */
> >  static int bperf_sync_counters(struct evsel *evsel)
> >  {
> > -       int num_cpu, i, cpu;
> > +       struct perf_cpu cpu;
> > +       int idx;
> > +
> > +       perf_cpu_map__for_each_cpu(cpu, idx, evsel->core.cpus)
> > +               bperf_trigger_reading(evsel->bperf_leader_prog_fd,
> > cpu.cpu);
> > 
> > -       num_cpu = perf_cpu_map__nr(all_cpu_map);
> > -       for (i = 0; i < num_cpu; i++) {
> > -               cpu = perf_cpu_map__cpu(all_cpu_map, i).cpu;
> > -               bperf_trigger_reading(evsel->bperf_leader_prog_fd,
> > cpu);
> > -       }
> >         return 0;
> >  }
> > 
> > diff --git a/tools/perf/util/bpf_counter_cgroup.c
> > b/tools/perf/util/bpf_counter_cgroup.c
> > index ed6a29b106b4..690be3ce3e11 100644
> > --- a/tools/perf/util/bpf_counter_cgroup.c
> > +++ b/tools/perf/util/bpf_counter_cgroup.c
> > @@ -186,7 +186,8 @@ static int bperf_cgrp__load(struct evsel
> > *evsel,
> >  }
> > 
> >  static int bperf_cgrp__install_pe(struct evsel *evsel
> > __maybe_unused,
> > -                                 int cpu __maybe_unused, int fd
> > __maybe_unused)
> > +                                 int cpu_map_idx __maybe_unused,
> > +                                 int fd __maybe_unused)
> >  {
> >         /* nothing to do */
> >         return 0;
> > --
> > 2.51.0.618.g983fd99d29-goog
> > 

Re: [PATCH v1 2/2] perf bpf_counter: Fix handling of cpumap fixing hybrid

[Ian Rogers]

On Mon, Oct 6, 2025 at 12:57 PM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> On Mon, Oct 06, 2025 at 09:18:22AM -0700, Ian Rogers wrote:
> > On Wed, Oct 1, 2025 at 11:12 AM Ian Rogers <irogers@google.com> wrote:
> > >
> > > Don't open evsels on all CPUs, open them just on the CPUs they
> > > support. This avoids opening say an e-core event on a p-core and
> > > getting a failure - achieve this by getting rid of the "all_cpu_map".
> > >
> > > In install_pe functions don't use the cpu_map_idx as a CPU number,
> > > translate the cpu_map_idx, which is a dense index into the cpu_map
> > > skipping holes at the beginning, to a proper CPU number.
> > >
> > > Before:
> > > ```
> > > $ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
> > >
> > >  Performance counter stats for 'system wide':
> > >
> > >    <not supported>      cpu_atom/cycles/
> > >        566,270,672      cpu_core/cycles/
> > >    <not supported>      cpu_atom/instructions/
> > >        572,792,836      cpu_core/instructions/           #    1.01  insn per cycle
> > >
> > >        1.001595384 seconds time elapsed
> > > ```
> > >
> > > After:
> > > ```
> > > $ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1
> > >
> > >  Performance counter stats for 'system wide':
> > >
> > >        443,299,201      cpu_atom/cycles/
> > >      1,233,919,737      cpu_core/cycles/
> > >        213,634,112      cpu_atom/instructions/           #    0.48  insn per cycle
> > >      2,758,965,527      cpu_core/instructions/           #    2.24  insn per cycle
> > >
> > >        1.001699485 seconds time elapsed
> > > ```
> > >
> > > Fixes: 7fac83aaf2ee ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF")
> > > Signed-off-by: Ian Rogers <irogers@google.com>
> >
> > +Thomas Falcon
> >
> > I think it'd be nice to get this quite major fix for
> > --bpf-counters/bperf for hybrid architectures into v6.18 and stable
> > builds. Thomas would it be possible for you to give a Tested-by tag
> > using the reproduction in the commit message?
>
> Its even already in linux-next:
>
> ⬢ [acme@toolbx perf-tools-next]$ git log -5 --oneline linux-next/master tools/perf/util/bpf_counter.c
> b91917c0c6fa6df9 perf bpf_counter: Fix handling of cpumap fixing hybrid
> 8c519a825b4add85 perf bpf_counter: Move header declarations into C code
> 07dc3a6de33098b0 perf stat: Support inherit events during fork() for bperf
> effe957c6bb70cac libperf cpumap: Replace usage of perf_cpu_map__new(NULL) with perf_cpu_map__new_online_cpus()
> b84b3f47921568a8 perf bpf_counter: Fix a few memory leaks
> ⬢ [acme@toolbx perf-tools-next]$

Oh, thanks! Sorry for missing it. Thanks Thomas for the tag!

Ian