perf config: Document the PERF_CONFIG environment variable

There was a provision for setting this variable, but not the
getenv("PERF_CONFIG") call to set it, as this was fixed in the previous
cset, document that it can be used to ask for using an alternative
.perfconfig file or to disable reading whatever file exists in the
system or home directory, i.e. using:

  export PERF_CONFIG=/dev/null

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Link: https://lkml.kernel.org/n/tip-0u4o967hsk7j0o50zp9ctn89@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2019-07-30 11:30:37 -03:00
parent 61a461fcbd
commit 5de9e5fda0

View File

@ -40,6 +40,10 @@ The '$HOME/.perfconfig' file is used to store a per-user configuration.
The file '$(sysconfdir)/perfconfig' can be used to
store a system-wide default configuration.
One an disable reading config files by setting the PERF_CONFIG environment
variable to /dev/null, or provide an alternate config file by setting that
variable.
When reading or writing, the values are read from the system and user
configuration files by default, and options '--system' and '--user'
can be used to tell the command to read from or write to only that location.