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=-12.0 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS 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 82EFEC43387 for ; Thu, 20 Dec 2018 18:15:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60B65218D9 for ; Thu, 20 Dec 2018 18:15:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731482AbeLTSP3 (ORCPT ); Thu, 20 Dec 2018 13:15:29 -0500 Received: from terminus.zytor.com ([198.137.202.136]:50637 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730351AbeLTSP2 (ORCPT ); Thu, 20 Dec 2018 13:15:28 -0500 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id wBKIFBGJ3682905 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 20 Dec 2018 10:15:11 -0800 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id wBKIFAQl3682902; Thu, 20 Dec 2018 10:15:10 -0800 Date: Thu, 20 Dec 2018 10:15:10 -0800 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Leo Yan Message-ID: Cc: namhyung@kernel.org, mathieu.poirier@linaro.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org, mingo@kernel.org, alexander.shishkin@linux.intel.com, mike.leach@linaro.org, jolsa@redhat.com, hpa@zytor.com, leo.yan@linaro.org, acme@redhat.com, tglx@linutronix.de, robert.walker@arm.com Reply-To: mike.leach@linaro.org, jolsa@redhat.com, namhyung@kernel.org, mathieu.poirier@linaro.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org, alexander.shishkin@linux.intel.com, mingo@kernel.org, leo.yan@linaro.org, robert.walker@arm.com, acme@redhat.com, tglx@linutronix.de, hpa@zytor.com In-Reply-To: <1544513908-16805-7-git-send-email-leo.yan@linaro.org> References: <1544513908-16805-7-git-send-email-leo.yan@linaro.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf cs-etm: Treat NO_SYNC element as trace discontinuity Git-Commit-ID: 37bb37168dc1b1f5e3ac791aeecd14ef980764fd X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 37bb37168dc1b1f5e3ac791aeecd14ef980764fd Gitweb: https://git.kernel.org/tip/37bb37168dc1b1f5e3ac791aeecd14ef980764fd Author: Leo Yan AuthorDate: Tue, 11 Dec 2018 15:38:26 +0800 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 18 Dec 2018 12:23:59 -0300 perf cs-etm: Treat NO_SYNC element as trace discontinuity The CoreSight tracer driver might insert barrier packets between different buffers, thus the decoder can spot the boundaries based on the barrier packet; it is possible for the decoder to hit a barrier packet and emit a NO_SYNC element, then the decoder will find a periodic synchronisation point inside that next trace block that starts the trace again but does not have the TRACE_ON element as indicator - usually because this trace block has wrapped the buffer so we have lost the original point when the trace was enabled. In the first case it causes the insertion of a OCSD_GEN_TRC_ELEM_NO_SYNC in the middle of the tracing stream, but as we were not handling the NO_SYNC element properly this ends up making users miss the discontinuity indications. Though OCSD_GEN_TRC_ELEM_NO_SYNC is different from CS_ETM_TRACE_ON when output from the decoder, both indicate that the trace data is discontinuous; this patch treats OCSD_GEN_TRC_ELEM_NO_SYNC as a trace discontinuity and generates a CS_ETM_DISCONTINUITY packet for it, so cs-etm can handle the discontinuity for this case, finally it saves the last trace data for the previous trace block and restart samples for the new block. Signed-off-by: Leo Yan Reviewed-by: Mathieu Poirier Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mike Leach Cc: Namhyung Kim Cc: Robert Walker Cc: coresight ml Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1544513908-16805-7-git-send-email-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/cs-etm-decoder/cs-etm-decoder.c | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c index 1039f364f4cc..bee026e76a4c 100644 --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c @@ -410,7 +410,6 @@ static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer( case OCSD_GEN_TRC_ELEM_UNKNOWN: break; case OCSD_GEN_TRC_ELEM_NO_SYNC: - break; case OCSD_GEN_TRC_ELEM_TRACE_ON: resp = cs_etm_decoder__buffer_discontinuity(decoder, trace_chan_id);