tree e03dfb35a8cade9258f72d097f48ef49ac1a14c4
parent 84c104ad429c8a474b93dd374815d1c238032fa8
author Andy Isaacson <adi@hexapodia.org> 1276313775 -0700
committer Arnaldo Carvalho de Melo <acme@redhat.com> 1276793754 -0300

perf session: fix error message on failure to open perf.data

If we cannot open our data file, print strerror(errno) for a more
comprehensible error message; and only suggest 'perf record' on ENOENT.

In particular, this fixes the nonsensical advice when:

    % sudo perf record sleep 1
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.009 MB perf.data (~381 samples) ]
    % perf trace
    failed to open file: perf.data  (try 'perf record' first)
    %

Cc: Ingo Molnar <mingo@elte.hu>
LPU-Reference: <20100612033615.GA24731@hexapodia.org>
Signed-off-by: Andy Isaacson <adi@hexapodia.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>