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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 B3FC5C2D0A3 for ; Wed, 4 Nov 2020 09:43:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C169221F9 for ; Wed, 4 Nov 2020 09:43:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="mteQwTSr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728821AbgKDJnD (ORCPT ); Wed, 4 Nov 2020 04:43:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728523AbgKDJnA (ORCPT ); Wed, 4 Nov 2020 04:43:00 -0500 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94670C0613D3 for ; Wed, 4 Nov 2020 01:43:00 -0800 (PST) Received: by mail-pl1-x642.google.com with SMTP id 1so10045527ple.2 for ; Wed, 04 Nov 2020 01:43:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=ZZTEvRl34/ltG27zu0i38hIQPnfchyj04AqsxWgKGqo=; b=mteQwTSrrLAF55P0uCUdUPSgG4mJ8q/gbQ7Ce+xgshakURElmVD/KzME0Plvo9F6MR Sd8e0GdWeacRcHjmq4FKBOIW/g6ntqO1mv9uDq0sJwz2IuGemG/mLF+COydE+QcBvgnc ZwalPjZFH3QOsOq6B6bvCSh0Q9pTa65QxHBMsB7Cmi8kj6LaSM0Z9HF8Hve0o6TnJ5md naSBOCK4KqlQu0Wvi6NaReE96MA+NBi0qoQ8wB+7EjMEqW30yqRC8svJKP9ndTKz1Yxb PvvlPaHl46asJe5O7vQhvbJaq/TgXuOgAYPT+5BnBXJeOgi0zCDme60UD5eImNmTAo+f AOpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=ZZTEvRl34/ltG27zu0i38hIQPnfchyj04AqsxWgKGqo=; b=dFNdJhB3Xn73YWyIju56FShncrYIZiTAJxL3kcFVOmmx7n69AFA7A9MMDjeMcRTbBZ HKttykpPdclPSklBfdPZAfry7QqNW+xUwAn3na7FwD9xjSwxAOe8NDyyT6FarkNqFLe0 rHi9qZmDa09rpDeASiAVtq+PsQP9k7JOrfbQ98oahK5AU2aikDLrs2DItH72cpJG+q9v 7QjwBxWpv5mr4BJKVXdIpL0MesGlHPxCkQ+LGMZHLVQneKWtnEygddR95CHKVwfgBqYD FDGw21O4kA10IJXISippdxZ+WLGSj84I4EGKkxZBbYTM2zb7h9vj7+YHHr0ANsnP5hDo qLAQ== X-Gm-Message-State: AOAM530CFK2Ba69UkcLQtCvBG+KVfncorBNY8xsajFMq0Nr07ZlySxCI LcSLv9boTTKQQi18myVfe3bmxw== X-Google-Smtp-Source: ABdhPJw5JN5TrdNWWI06PIUcmTLwFWzhpVkB0uiZJdER28unFX9dgu+PSs143NdEy3S/lTwYIp4+jA== X-Received: by 2002:a17:902:8347:b029:d5:de7a:db11 with SMTP id z7-20020a1709028347b02900d5de7adb11mr27790701pln.2.1604482980142; Wed, 04 Nov 2020 01:43:00 -0800 (PST) Received: from localhost ([2600:3c01::f03c:91ff:fe8a:bb03]) by smtp.gmail.com with ESMTPSA id j13sm1884835pfd.97.2020.11.04.01.42.59 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Wed, 04 Nov 2020 01:42:59 -0800 (PST) From: Leo Yan To: Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Frederic Weisbecker , Hitoshi Mitake , linux-kernel@vger.kernel.org Cc: Leo Yan Subject: [PATCH v3 2/2] perf lock: Don't free "lock_seq_stat" if read_count isn't zero Date: Wed, 4 Nov 2020 17:42:29 +0800 Message-Id: <20201104094229.17509-2-leo.yan@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201104094229.17509-1-leo.yan@linaro.org> References: <20201104094229.17509-1-leo.yan@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When execute command "perf lock report", it hits failure and outputs log as follows: perf: builtin-lock.c:623: report_lock_release_event: Assertion `!(seq->read_count < 0)' failed. Aborted This is an imbalance issue. The locking sequence structure "lock_seq_stat" contains the reader counter and it is used to check if the locking sequence is balance or not between acquiring and releasing. If the tool wrongly frees "lock_seq_stat" when "read_count" isn't zero, the "read_count" will be reset to zero when allocate a new structure at the next time; thus it causes the wrong counting for reader and finally results in imbalance issue. To fix this issue, if detects "read_count" is not zero (means still have read user in the locking sequence), goto the "end" tag to skip freeing structure "lock_seq_stat". Fixes: e4cef1f65061 ("perf lock: Fix state machine to recognize lock sequence") Signed-off-by: Leo Yan Acked-by: Jiri Olsa --- v3: Corrected "Fixes" tag to reflect the first patch causing the issue (Jiri) tools/perf/builtin-lock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c index 5cecc1ad78e1..a2f1e53f37a7 100644 --- a/tools/perf/builtin-lock.c +++ b/tools/perf/builtin-lock.c @@ -621,7 +621,7 @@ static int report_lock_release_event(struct evsel *evsel, case SEQ_STATE_READ_ACQUIRED: seq->read_count--; BUG_ON(seq->read_count < 0); - if (!seq->read_count) { + if (seq->read_count) { ls->nr_release++; goto end; } -- 2.17.1