Perf buildid-cache gives a confusing message

[Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>]

Hi,
(Sorry, I missed CC to LKML)

I've found a bit odd perf-buildid-cache behavior. It seems
to be as designed, but also a bit confusing.

Issue: perf-buildid-cache's --update and --remove operations
refer the current existing binary at given path. This means
if we update the old binary, it couldn't remove nor update
the buildid-cache.

Here is the example,
  ----
  [mhiramat@localhost perf]$ ./perf buildid-cache -v --add ./perf
  Adding 51d0731187917e27fd733f2f6f34777cddbaec0f ./perf: Ok  <-- (*)
  [mhiramat@localhost perf]$ rm perf
  [mhiramat@localhost perf]$ make clean
  [mhiramat@localhost perf]$ make
  [mhiramat@localhost perf]$ ./perf buildid-cache -v --update ./perf
  Updating 45a97daa65f9c58adeb34af4158a6dde747de49b ./perf: FAIL <-- (*)
  ./perf wasn't in the cache
  [mhiramat@localhost perf]$ ./perf buildid-cache -v --remove ./perf
  Removing 45a97daa65f9c58adeb34af4158a6dde747de49b ./perf: FAIL <-- (*)
  ./perf wasn't in the cache
  ----
Both --update and --remove are failed after updating local binary.
Note that (*) are verbose message, without -v we don't see that.

I know this is the designed behavior, buildid-cache manages binaries
based on its build-id, not its path. However, it seems confusing.

So, I'd like to suggest to fix --update FILE to add new binary to cache
when there is no current binary cache (this will fix the first FAIL),
and add --remove-all FILE to remove all existing buildid cache about FILE
(path-based cleanup).
What would you think about that?

Thank you,
-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com