From 674e18de7bde49129f7793728169e4ab8d6afcee Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Wed, 7 Mar 2018 16:02:24 +0200 Subject: perf intel-pt: Fix timestamp following overflow commit 91d29b288aed3406caf7c454bf2b898c96cfd177 upstream. timestamp_insn_cnt is used to estimate the timestamp based on the number of instructions since the last known timestamp. If the estimate is not accurate enough decoding might not be correctly synchronized with side-band events causing more trace errors. However there are always timestamps following an overflow, so the estimate is not needed and can indeed result in more errors. Suppress the estimate by setting timestamp_insn_cnt to zero. Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1520431349-30689-5-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman --- tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 1 + 1 file changed, 1 insertion(+) (limited to 'tools') diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c index 5e4d0bbafc8b..f9157aed1289 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -1378,6 +1378,7 @@ static int intel_pt_overflow(struct intel_pt_decoder *decoder) intel_pt_clear_tx_flags(decoder); decoder->have_tma = false; decoder->cbr = 0; + decoder->timestamp_insn_cnt = 0; decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC; decoder->overflow = true; return -EOVERFLOW; -- cgit v1.2.3