Yang Jihong 72108c0b9c 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 <yangjihong1@huawei.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231031105523.1472558-1-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-11-28 14:14:53 -03:00

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2.6 KiB
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perf(1)
=======
NAME
----
perf - Performance analysis tools for Linux
SYNOPSIS
--------
[verse]
'perf' [--version] [--help] [OPTIONS] COMMAND [ARGS]
OPTIONS
-------
-h::
--help::
Run perf help command.
-v::
--version::
Display perf version.
-vv::
Print the compiled-in status of libraries.
--exec-path::
Display or set exec path.
--html-path::
Display html documentation path.
-p::
--paginate::
Set up pager.
--no-pager::
Do not set pager.
--buildid-dir::
Setup buildid cache directory. It has higher priority
than buildid.dir config file option.
--list-cmds::
List the most commonly used perf commands.
--list-opts::
List available perf options.
--debugfs-dir::
Set debugfs directory or set environment variable PERF_DEBUGFS_DIR.
--debug::
Setup debug variable (see list below) in value
range (0, 10). Use like:
--debug verbose # sets verbose = 1
--debug verbose=2 # sets verbose = 2
List of debug variables allowed to set:
verbose - general debug messages
ordered-events - ordered events object debug messages
data-convert - data convert command debug messages
stderr - write debug output (option -v) to stderr
in browser mode
perf-event-open - Print perf_event_open() arguments and
return value
--debug-file::
Write debug output to a specified file.
DESCRIPTION
-----------
Performance counters for Linux are a new kernel-based subsystem
that provide a framework for all things performance analysis. It
covers hardware level (CPU/PMU, Performance Monitoring Unit) features
and software features (software counters, tracepoints) as well.
SEE ALSO
--------
linkperf:perf-stat[1], linkperf:perf-top[1],
linkperf:perf-record[1], linkperf:perf-report[1],
linkperf:perf-list[1]
linkperf:perf-annotate[1],linkperf:perf-archive[1],linkperf:perf-arm-spe[1],
linkperf:perf-bench[1], linkperf:perf-buildid-cache[1],
linkperf:perf-buildid-list[1], linkperf:perf-c2c[1],
linkperf:perf-config[1], linkperf:perf-data[1], linkperf:perf-diff[1],
linkperf:perf-evlist[1], linkperf:perf-ftrace[1],
linkperf:perf-help[1], linkperf:perf-inject[1],
linkperf:perf-intel-pt[1], linkperf:perf-iostat[1], linkperf:perf-kallsyms[1],
linkperf:perf-kmem[1], linkperf:perf-kvm[1], linkperf:perf-lock[1],
linkperf:perf-mem[1], linkperf:perf-probe[1], linkperf:perf-sched[1],
linkperf:perf-script[1], linkperf:perf-test[1],
linkperf:perf-trace[1], linkperf:perf-version[1]