• Arnaldo Carvalho de Melo's avatar
    perf tools: Propagate perf_config() errors · ecc4c561
    Arnaldo Carvalho de Melo authored
    Previously these were being ignored, sometimes silently.
    
    Stop doing that, emitting debug messages and handling the errors.
    
    Testing it:
    
      $ cat ~/.perfconfig
      cat: /home/acme/.perfconfig: No such file or directory
      $ perf stat -e cycles usleep 1
    
       Performance counter stats for 'usleep 1':
    
               938,996      cycles:u
    
           0.003813731 seconds time elapsed
    
      $ perf top --stdio
      Error:
      You may not have permission to collect system-wide stats.
    
      Consider tweaking /proc/sys/kernel/perf_event_paranoid,
      <SNIP>
      [ perf record: Captured and wrote 0.019 MB perf.data (7 samples) ]
      [acme@jouet linux]$ perf report --stdio
      # To display the perf.data header info, please use --header/--header-only options.
      # Overhead  Command  Shared Object      Symbol
      # ........  .......  .................  .........................
        71.77%  usleep   libc-2.24.so       [.] _dl_addr
        27.07%  usleep   ld-2.24.so         [.] _dl_next_ld_env_entry
         1.13%  usleep   [kernel.kallsyms]  [k] page_fault
      $
      $ touch ~/.perfconfig
      $ ls -la ~/.perfconfig
      -rw-rw-r--. 1 acme acme 0 Jan 27 12:14 /home/acme/.perfconfig
      $
      $ perf stat -e instructions usleep 1
    
       Performance counter stats for 'usleep 1':
    
               244,610      instructions:u
    
           0.000805383 seconds time elapsed
    
      $
      [root@jouet ~]# chown acme.acme ~/.perfconfig
      [root@jouet ~]# perf stat -e cycles usleep 1
        Warning: File /root/.perfconfig not owned by current user or root, ignoring it.
    
       Performance counter stats for 'usleep 1':
    
               937,615      cycles
    
           0.000836931 seconds time elapsed
      #
    
    Cc: Adrian Hunter <adrian.hunter@intel.com>
    Cc: David Ahern <dsahern@gmail.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Wang Nan <wangnan0@huawei.com>
    Link: http://lkml.kernel.org/n/tip-j2rq96so6xdqlr8p8rd6a3jx@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    ecc4c561
llvm-utils.c 12.7 KB