perf tools: Add --debug-file option to redirect debug output

Currently, debug messages is output to stderr, add --debug-file option to
support redirection to a specified file.

Some test scenarios:

  # perf --list-opts
  --help --version --exec-path --html-path --paginate --no-pager --debugfs-dir --buildid-dir --list-cmds --list-opts --debug --debug-file

  # perf --debug-file
  No path given for --debug-file.

   Usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]

  # perf --debug-file /sys/perf.log record -v true
  Open debug file '/sys/perf.log' failed: Permission denied

   Usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]

  # perf --debug-file /tmp/perf.log record -v true
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.013 MB perf.data (26 samples) ]
  # cat /tmp/perf.log
  DEBUGINFOD_URLS=
  Using CPUID GenuineIntel-6-3E-4
  nr_cblocks: 0
  affinity: SYS
  mmap flush: 1
  comp level: 0
  mmap size 528384B
  Control descriptor is not initialized
  mmap size 528384B
  Looking at the vmlinux_path (8 entries long)
  Using /proc/kcore for kernel data
  Using /proc/kallsyms for symbols
  symbol:unmap_start file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:unmap_complete file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:map_start file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:map_complete file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:reloc_start file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:reloc_complete file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:init_start file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:init_complete file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:lll_lock_wait_private file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:lll_lock_wait file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:setjmp file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:longjmp file:(null) line:0 offset:0 return:0 lazy:(null)
  symbol:longjmp_target file:(null) line:0 offset:0 return:0 lazy:(null)
  failed to write feature HYBRID_TOPOLOGY

Signed-off-by: Yang Jihong <[email protected]>
Acked-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[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