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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 DFA6AC43381 for ; Tue, 12 Mar 2019 13:38:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A203D2075C for ; Tue, 12 Mar 2019 13:38:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YB31N7Nz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726280AbfCLNiE (ORCPT ); Tue, 12 Mar 2019 09:38:04 -0400 Received: from mail-yw1-f51.google.com ([209.85.161.51]:37879 "EHLO mail-yw1-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725774AbfCLNiD (ORCPT ); Tue, 12 Mar 2019 09:38:03 -0400 Received: by mail-yw1-f51.google.com with SMTP id w66so1372348ywd.4 for ; Tue, 12 Mar 2019 06:38:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=L1QKkfv9YJmkvJXos/3vTF+TvA86H1gHbGnjGtJKF3E=; b=YB31N7NzDDyehLwpWNHfB1/y0wy+OyWN1/RsAu+6Lr56NzlyZ4nU5aCEKXXwy3/MXQ mxfr52A71Ekl+PrniKjx+iObFznb/JZdLYH8BIzP3R16ORfsvePh5Jot86Q8TWmPveN9 9vheX2NWkU/e0QGVefADAR8/wQUb3f+MGZ7aFgf1isL2vAZovSNC8YZnTNO2PizCvUV2 /Ry7+xmga8Mj+RlfPH4ii3/iDvO0gdAje9Q6VvhU5dtxVuiVU9JQ0qOnLra7tF67ETs5 GVXl9P+hg+OW/cRKxX0zHOuuI5dhNMKHc59rGRnkeCBegrnW26Sit4r5+ipqrXlSs+J/ Z5dQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=L1QKkfv9YJmkvJXos/3vTF+TvA86H1gHbGnjGtJKF3E=; b=YYnoY/JhZOc6S+ZqciUWsDr2EKwF7nnjrspC323bmmemOY0y1UCq2BSihqz0QzuUKi nYuSo2EQr12bopD0gRgH5FE/9EpJgLSlZ5uN7HKXqQyvMzw2d/Io+JifzUXxOWPA43d4 2z6j25Vj5BWrpMJ62rPlMn2aB6UrJLW9pgkMWBngAWfPNEweaheJUepolRngYWnWHH3z yKceiAoLfD9+rRw/lSQ+lw2/oCmo0s3D8Qx8xKa6IFe1+ZkBD/grVK9jhGGcaowEs00u PMKVwiKIWqGiKtDYBkkgZqGnyVpHKkzV9byAFTp/E9Jcv2y7UpFBiRhGE98b44DVCSlI E7KA== X-Gm-Message-State: APjAAAWHJS9tIeP2mrdsduNvUZrlaMBuHm5pQjC1Aqrl3pPxeTJ5dsZZ vWPiim4ePABxSXKk23ceXmj405hIGRI+qJZ+TGyRgJUw X-Google-Smtp-Source: APXvYqz96KFz9spYxYoW6ZW9mSlCfCZsk72YjsjL8w2YjhEDDFGf98yCGhObLxRA70w/TJugOFfSo98NX5lojDACekM= X-Received: by 2002:a81:180b:: with SMTP id 11mr28257500ywy.431.1552397883111; Tue, 12 Mar 2019 06:38:03 -0700 (PDT) MIME-Version: 1.0 References: <20190219172156.syot6kfy37dzvrui@linutronix.de> In-Reply-To: <20190219172156.syot6kfy37dzvrui@linutronix.de> From: Yimin Deng Date: Tue, 12 Mar 2019 21:37:51 +0800 Message-ID: Subject: Re: Help me: deadlock reported in pthread_mutex_lock To: Sebastian Andrzej Siewior Cc: linux-rt-users@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org Hi Sebastian, Thank you for your concern! We also doubt that there's something wrong on the atomic operation or on cache line consistency on SMP. But it's really hard to confirm or to debug it because it's difficult to reproduce it. B.R. Yimin > On 2019-02-14 16:09:48 [+0800], Yimin Deng wrote: > > I could not image a scenario that lead to 3 different values on the > > same variable mutex->__data.__lock seen in 3 positions. > > It's very difficult to reproduce this issue (About 1 ~ several months > > for 1 reproducing). And we failed to reproduce it using small > > application. > > what are the chances that the atomic operations are not so atomic? > > > B.R. > > Yimin > > Sebastian