perf probe: Show better error message when failed to find variable

Indicate to check variable location range in error message when we got
failed to find the variable.

Before this patch:

  $ perf probe --add 'generic_perform_write+118 bytes'
  Failed to find the location of bytes at this address.
   Perhaps, it has been optimized out.
    Error: Failed to add events.

After this patch:

  $ perf probe --add 'generic_perform_write+118 bytes'
  Failed to find the location of the 'bytes' variable at this address.
   Perhaps it has been optimized out.
   Use -V with the --range option to show 'bytes' location range.
    Error: Failed to add events.

Signed-off-by: He Kuang <[email protected]>
Acked-by: Masami Hiramatsu <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Improve the error message based on lkml thread ]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions