From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58EFBC433ED for ; Thu, 29 Apr 2021 12:59:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 290B461424 for ; Thu, 29 Apr 2021 12:59:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239201AbhD2NAU (ORCPT ); Thu, 29 Apr 2021 09:00:20 -0400 Received: from mga17.intel.com ([192.55.52.151]:50859 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238780AbhD2NAJ (ORCPT ); Thu, 29 Apr 2021 09:00:09 -0400 IronPort-SDR: PDvHjcpJWnLHGbvHjo6OmsgngcgERTwIL27OJ9jmDeouOlu9NCNfYhG49GmXEZ0xYICl4eaHyN CreXNw82f+nA== X-IronPort-AV: E=McAfee;i="6200,9189,9969"; a="177107525" X-IronPort-AV: E=Sophos;i="5.82,259,1613462400"; d="scan'208";a="177107525" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Apr 2021 05:58:51 -0700 IronPort-SDR: 3/3b5QseZ4HsUftWd/EiooAuVWZlLihivT0V2hb/zuq8XC99+h8zs19K+v+wfnXZ88eAB1r9s0 mDWEbV1eN44Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,259,1613462400"; d="scan'208";a="537361675" Received: from ahunter-desktop.fi.intel.com ([10.237.72.174]) by orsmga004.jf.intel.com with ESMTP; 29 Apr 2021 05:58:50 -0700 From: Adrian Hunter To: Arnaldo Carvalho de Melo , Jiri Olsa , Andi Kleen Cc: linux-kernel@vger.kernel.org Subject: [PATCH 10/12] perf intel-pt: Better 7-byte timestamp wraparound logic Date: Thu, 29 Apr 2021 15:58:52 +0300 Message-Id: <20210429125854.13905-11-adrian.hunter@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210429125854.13905-1-adrian.hunter@intel.com> References: <20210429125854.13905-1-adrian.hunter@intel.com> Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A timestamp should not go backwards. If it does it is assumed that the 7-byte TSC packet value has wrapped. Improve that logic so that it will not allow the timestamp to go past the buffer timestamp (which is recorded when the buffer is copied out) Signed-off-by: Adrian Hunter --- tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) 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 ba5b5782acc1..b95312ec3832 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -1499,9 +1499,15 @@ static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder) timestamp = decoder->timestamp; } if (timestamp < decoder->timestamp) { - intel_pt_log_to("Wraparound timestamp", timestamp); - timestamp += (1ULL << 56); - decoder->tsc_timestamp = timestamp; + if (!decoder->buf_timestamp || + (timestamp + (1ULL << 56) < decoder->buf_timestamp)) { + intel_pt_log_to("Wraparound timestamp", timestamp); + timestamp += (1ULL << 56); + decoder->tsc_timestamp = timestamp; + } else { + intel_pt_log_to("Suppressing bad timestamp", timestamp); + timestamp = decoder->timestamp; + } } decoder->timestamp = timestamp; decoder->timestamp_insn_cnt = 0; -- 2.17.1