Commit 36dcf6ef authored by Adrian Hunter's avatar Adrian Hunter Committed by Greg Kroah-Hartman

perf intel-pt: Fix sample timestamp wrt non-taken branches

commit 1b6599a9 upstream.

The sample timestamp is updated to ensure that the timestamp represents
the time of the sample and not a branch that the decoder is still
walking towards. The sample timestamp is updated when the decoder
returns, but the decoder does not return for non-taken branches. Update
the sample timestamp then also.

Note that commit 3f04d98e ("perf intel-pt: Improve sample
timestamp") was also a stable fix and appears, for example, in v4.4
stable tree as commit a4ebb58f ("perf intel-pt: Improve sample
timestamp").
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org # v4.4+
Fixes: 3f04d98e ("perf intel-pt: Improve sample timestamp")
Link: http://lkml.kernel.org/r/20190510124143.27054-4-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 41be88f5
......@@ -1318,8 +1318,11 @@ static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
return 0;
}
decoder->ip += intel_pt_insn.length;
if (!decoder->tnt.count)
if (!decoder->tnt.count) {
decoder->sample_timestamp = decoder->timestamp;
decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
return -EAGAIN;
}
decoder->tnt.payload <<= 1;
continue;
}
......
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