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 7F4ADC4363D for ; Wed, 21 Oct 2020 00:26:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19A5B22242 for ; Wed, 21 Oct 2020 00:26:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="kmy3R4cF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439660AbgJUA0l (ORCPT ); Tue, 20 Oct 2020 20:26:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439616AbgJUA0k (ORCPT ); Tue, 20 Oct 2020 20:26:40 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07576C0613CE for ; Tue, 20 Oct 2020 17:26:40 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id l18so387935pgg.0 for ; Tue, 20 Oct 2020 17:26:40 -0700 (PDT) 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=UdwZtavXZ+Nr+Yg8C050ouEBSFK5iEg6NJ5eRk4E26c=; b=kmy3R4cFRHdnUMj4lX6EkxXlxO0e/WsS2dOTP+YsXBp4s5SLB7pyhNr7BAsKuGtj0y McucWYt2EGQmWXKC3yN5mC/mzHbTiFWGEP568elzPOGQQyo/CK87uFlWI8WoIHGGQAOA uLnFKTglUUfNx4AYm5YD7Bai6ejm+eX2jVlgzdPmetVyZU7vy/0St1qLYtpWlGBFvi5+ THMk0zWEgRrPuopaIIQeYo49wH2sfzSx6BuSSotoSmNgN9C5fwz0ytpL/3GLhmLEFYGi KRX/cfA2AxUYeLrgyV8zAQt/SaAzCH5OR6IkmoHQ3+Tdin+30pQzxj5nvjQexr1Kgw/y ceag== 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=UdwZtavXZ+Nr+Yg8C050ouEBSFK5iEg6NJ5eRk4E26c=; b=rMhnA7pc1KuCjVi6V8I+wkhzvTKg0UeYpFGVPnom02RKPTqfPjnKaEIFLW5BMcsCO0 wfLzxG5dn1PYywINK6OR7DfKgG6hY9LnOzflDnOwbMmqBRrUOgfcJTKurKKc8wu+vZ63 2d/Rx3CEY/BbqguqBYHVQ/G2qOP+db+kqDr3CR+QLMrvYl8aeqYVm8Um7TSJ2kXjRJEu afjLh+hzgJS1WVDr2v4FgL1gji8ywHdC+4ogMw0tKDcvv5Ksp0elaWHq9qbbIH/42P6n YphwLG/fvLzHoKU4soVA4vs+0I7KBO6XDsdicYXa5rgU7NxbdV7yPxdlP5BJZQkIGdQ3 Nc9g== X-Gm-Message-State: AOAM530Y0r/AkYb8gK5HSMOb/gm++f9cCbCyqY7DxGr1tgIa+7Y2aQwF QLj/a0iZn8XxQjSAcg+LpYyodg== X-Google-Smtp-Source: ABdhPJxfOCetMUqH8m6a6JNYo2mthcQnxyVF52JXElZqp5BetNnsFu471+x3X0vDvrE3V7RVdTWWGA== X-Received: by 2002:a63:c806:: with SMTP id z6mr736707pgg.430.1603239999512; Tue, 20 Oct 2020 17:26:39 -0700 (PDT) Received: from localhost ([2600:3c01::f03c:91ff:fe8a:bb03]) by smtp.gmail.com with ESMTPSA id k13sm173222pfh.177.2020.10.20.17.26.38 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 20 Oct 2020 17:26:39 -0700 (PDT) From: Leo Yan To: Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-kernel@vger.kernel.org Cc: Leo Yan Subject: [PATCH 2/2] perf lock: Don't free "lock_seq_stat" if read_count isn't zero Date: Wed, 21 Oct 2020 08:26:19 +0800 Message-Id: <20201021002619.28072-2-leo.yan@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201021002619.28072-1-leo.yan@linaro.org> References: <20201021002619.28072-1-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". Signed-off-by: Leo Yan --- 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