perf record offcpu: Constify control data for BPF

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 record --off-cpu
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 1.807 MB perf.data (5645 samples) ]

  root@x1:~# perf evlist
  cpu_atom/cycles/P
  cpu_core/cycles/P
  offcpu-time
  dummy:u
  root@x1:~# perf evlist -v
  cpu_atom/cycles/P: type: 0 (PERF_TYPE_HARDWARE), size: 136, config: 0xa00000000, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD|IDENTIFIER, read_format: ID|LOST, disabled: 1, inherit: 1, freq: 1, precise_ip: 3, sample_id_all: 1
  cpu_core/cycles/P: type: 0 (PERF_TYPE_HARDWARE), size: 136, config: 0x400000000, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD|IDENTIFIER, read_format: ID|LOST, disabled: 1, inherit: 1, freq: 1, precise_ip: 3, sample_id_all: 1
  offcpu-time: type: 1 (software), size: 136, config: 0xa (PERF_COUNT_SW_BPF_OUTPUT), { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD|IDENTIFIER, read_format: ID|LOST, disabled: 1, inherit: 1, freq: 1, sample_id_all: 1
  dummy:u: type: 1 (software), size: 136, config: 0x9 (PERF_COUNT_SW_DUMMY), { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|IDENTIFIER, read_format: ID|LOST, inherit: 1, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
  root@x1:~# perf trace -e bpf --max-events 5 perf record --off-cpu
       0.000 ( 0.015 ms): :2949124/2949124 bpf(cmd: 36, uattr: 0x7ffefc6dbe30, size: 8)          = -1 EOPNOTSUPP (Operation not supported)
       0.031 ( 0.115 ms): :2949124/2949124 bpf(cmd: PROG_LOAD, uattr: 0x7ffefc6dbb60, size: 148) = 14
       0.159 ( 0.037 ms): :2949124/2949124 bpf(cmd: PROG_LOAD, uattr: 0x7ffefc6dbc20, size: 148) = 14
      23.868 ( 0.144 ms): perf/2949124 bpf(cmd: PROG_LOAD, uattr: 0x7ffefc6dbad0, size: 148)     = 14
      24.027 ( 0.014 ms): perf/2949124 bpf(uattr: 0x7ffefc6dbc80, size: 80)                      = 14
  root@x1:~#

Signed-off-by: Namhyung Kim <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Song Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions