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perf kwork: Constify control data for BPF

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The control knobs set before loading BPF programs should be declared as
'const volatile' so that it can be optimized by the BPF core.

Committer testing:

  root@x1:~# perf kwork report --use-bpf
  Starting trace, Hit <Ctrl+C> to stop and report
  ^C
    Kwork Name                     | Cpu  | Total Runtime | Count     | Max runtime   | Max runtime start   | Max runtime end     |
   --------------------------------------------------------------------------------------------------------------------------------
    (w)intel_atomic_commit_work [  | 0009 |     18.680 ms |         2 |     18.553 ms |     362410.681580 s |     362410.700133 s |
    (w)pm_runtime_work             | 0007 |     13.300 ms |         1 |     13.300 ms |     362410.254996 s |     362410.268295 s |
    (w)intel_atomic_commit_work [  | 0009 |      9.846 ms |         2 |      9.717 ms |     362410.172352 s |     362410.182069 s |
    (w)acpi_ec_event_processor     | 0002 |      8.106 ms |         1 |      8.106 ms |     362410.463187 s |     362410.471293 s |
    (s)SCHED:7                     | 0000 |      1.351 ms |       106 |      0.063 ms |     362410.658017 s |     362410.658080 s |
    i915:157                       | 0008 |      0.994 ms |        13 |      0.361 ms |     362411.222125 s |     362411.222486 s |
    (s)SCHED:7                     | 0001 |      0.703 ms |        98 |      0.047 ms |     362410.245004 s |     362410.245051 s |
    (s)SCHED:7                     | 0005 |      0.674 ms |        42 |      0.074 ms |     362411.483039 s |     362411.483113 s |
    (s)NET_RX:3                    | 0001 |      0.556 ms |        10 |      0.079 ms |     362411.066388 s |     362411.066467 s |
  <SNIP>

  root@x1:~# perf trace -e bpf --max-events 5 perf kwork report --use-bpf
       0.000 ( 0.016 ms): perf/2948007 bpf(cmd: 36, uattr: 0x7ffededa6660, size: 8)          = -1 EOPNOTSUPP (Operation not supported)
       0.026 ( 0.106 ms): perf/2948007 bpf(cmd: PROG_LOAD, uattr: 0x7ffededa6390, size: 148) = 12
       0.152 ( 0.032 ms): perf/2948007 bpf(cmd: PROG_LOAD, uattr: 0x7ffededa6450, size: 148) = 12
      26.247 ( 0.138 ms): perf/2948007 bpf(cmd: PROG_LOAD, uattr: 0x7ffededa6300, size: 148) = 12
      26.396 ( 0.012 ms): perf/2948007 bpf(uattr: 0x7ffededa64b0, size: 80)                  = 12
  Starting trace, Hit <Ctrl+C> to stop and report
  root@x1:~#

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Yang Jihong <yangjihong@bytedance.com>
Link: https://lore.kernel.org/r/20240902200515.2103769-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2024-09-02 13:05:13 -07:00 committed by Arnaldo Carvalho de Melo
parent ac5a23b2f2
commit 066fd84087
4 changed files with 13 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
tools/perf/util/bpf_kwork.c
View File

@ -176,8 +176,6 @@ static int setup_filters(struct perf_kwork *kwork)
bpf_map_update_elem(fd, &cpu.cpu, &val, BPF_ANY); bpf_map_update_elem(fd, &cpu.cpu, &val, BPF_ANY);
} }
perf_cpu_map__put(map); perf_cpu_map__put(map);
skel->bss->has_cpu_filter = 1;
} }
if (kwork->profile_name != NULL) { if (kwork->profile_name != NULL) {
@ -197,8 +195,6 @@ static int setup_filters(struct perf_kwork *kwork)
key = 0; key = 0;
bpf_map_update_elem(fd, &key, kwork->profile_name, BPF_ANY); bpf_map_update_elem(fd, &key, kwork->profile_name, BPF_ANY);
skel->bss->has_name_filter = 1;
} }
return 0; return 0;
@ -239,6 +235,11 @@ int perf_kwork__trace_prepare_bpf(struct perf_kwork *kwork)
class_bpf->load_prepare(kwork); class_bpf->load_prepare(kwork);
} }
if (kwork->cpu_list != NULL)
skel->rodata->has_cpu_filter = 1;
if (kwork->profile_name != NULL)
skel->rodata->has_name_filter = 1;
if (kwork_trace_bpf__load(skel)) { if (kwork_trace_bpf__load(skel)) {
pr_debug("Failed to load kwork trace skeleton\n"); pr_debug("Failed to load kwork trace skeleton\n");
goto out; goto out;

7
tools/perf/util/bpf_kwork_top.c
View File

@ -151,14 +151,12 @@ static int setup_filters(struct perf_kwork *kwork)
bpf_map_update_elem(fd, &cpu.cpu, &val, BPF_ANY); bpf_map_update_elem(fd, &cpu.cpu, &val, BPF_ANY);
} }
perf_cpu_map__put(map); perf_cpu_map__put(map);
skel->bss->has_cpu_filter = 1;
} }
return 0; return 0;
} }
int perf_kwork__top_prepare_bpf(struct perf_kwork *kwork __maybe_unused) int perf_kwork__top_prepare_bpf(struct perf_kwork *kwork)
{ {
struct bpf_program *prog; struct bpf_program *prog;
struct kwork_class *class; struct kwork_class *class;
@ -193,6 +191,9 @@ int perf_kwork__top_prepare_bpf(struct perf_kwork *kwork __maybe_unused)
class_bpf->load_prepare(); class_bpf->load_prepare();
} }
if (kwork->cpu_list)
skel->rodata->has_cpu_filter = 1;
if (kwork_top_bpf__load(skel)) { if (kwork_top_bpf__load(skel)) {
pr_debug("Failed to load kwork top skeleton\n"); pr_debug("Failed to load kwork top skeleton\n");
goto out; goto out;

2
tools/perf/util/bpf_skel/kwork_top.bpf.c
View File

@ -84,7 +84,7 @@ struct {
int enabled = 0; int enabled = 0;
int has_cpu_filter = 0; const volatile int has_cpu_filter = 0;
__u64 from_timestamp = 0; __u64 from_timestamp = 0;
__u64 to_timestamp = 0; __u64 to_timestamp = 0;

5
tools/perf/util/bpf_skel/kwork_trace.bpf.c
View File

@ -68,8 +68,9 @@ struct {
} perf_kwork_name_filter SEC(".maps"); } perf_kwork_name_filter SEC(".maps");
int enabled = 0; int enabled = 0;
int has_cpu_filter = 0;
int has_name_filter = 0; const volatile int has_cpu_filter = 0;
const volatile int has_name_filter = 0;
static __always_inline int local_strncmp(const char *s1, static __always_inline int local_strncmp(const char *s1,
unsigned int sz, const char *s2) unsigned int sz, const char *s2)