[PATCH 7/7] perf session: fix error message on failure to open perf.data
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From: Arnaldo Carvalho de Melo on 17 Jun 2010 16:50 From: Andy Isaacson <adi(a)hexapodia.org> 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(a)elte.hu> LPU-Reference: <20100612033615.GA24731(a)hexapodia.org> Signed-off-by: Andy Isaacson <adi(a)hexapodia.org> Signed-off-by: Arnaldo Carvalho de Melo <acme(a)redhat.com> --- tools/perf/util/session.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 8f83a18..0564a5c 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -27,8 +27,10 @@ static int perf_session__open(struct perf_session *self, bool force) self->fd = open(self->filename, O_RDONLY); if (self->fd < 0) { - pr_err("failed to open file: %s", self->filename); - if (!strcmp(self->filename, "perf.data")) + int err = errno; + + pr_err("failed to open %s: %s", self->filename, strerror(err)); + if (err == ENOENT && !strcmp(self->filename, "perf.data")) pr_err(" (try 'perf record' first)"); pr_err("\n"); return -errno; -- 1.6.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |