From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C87E0211291 for ; Wed, 19 Feb 2025 20:20:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739996448; cv=none; b=apwEd5Q2R7jtDr/PXKttONpSrbY59Ako9iwwKRp0xQLSVvhUv1z4ZEAEy2VeqY+xOsdWvdcWSeP/2RTygM85Xyt5nCSQDys22KMrnDEYsklTLFkRPCR1MAwQpiww4mBwHzAMlVEBXOQz2YvCaD6FzXzEU4vqSHwLyFR2nwOA8z4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739996448; c=relaxed/simple; bh=ygbIrb1kmuPASL99Lj6Ag7c41897c0GbMeyTzSauQQY=; h=From:Message-ID:Date:MIME-Version:Subject:To:Cc:References: In-Reply-To:Content-Type; b=ZcP0BEKJ4gHwnouOzwLNdyizjgcW7WFYxQ9ZzgI6Em7VgslcgzKwHNIZ3W87ytoon4nA5BOu+eZ6cz3+z4lQtLLVzQ3Wg8adfMAzJU/GjvQGRk1xzCLdwQG/ebP2QsR0/KmmkmAtzbftqXbBGpTNjAWNye1wX4hNq2nolhhthj4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=b9a6D7Uq; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="b9a6D7Uq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1739996445; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=m56pAf3/12TQHH7eDD4tbpCjv5t0oQOoxHOFLr4f6XE=; b=b9a6D7UqRouDF4mcVirOBW9q0QUfattgmOReKGsIiWm1cXNTneWFwF6ebNNkk0b9sT13O5 R0ymjiG3y+VpqS6+vKF7XO3MFFIs6YORZ8Q4VJkFiDKfpu7xJMCTjL6ivt1cSDdf7S8Fs1 shFvL7potE+gvml96uzFHhx4YNrYxk8= Received: from mail-oa1-f69.google.com (mail-oa1-f69.google.com [209.85.160.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-526-oXMtMI1hMOiK1j6B5l87eQ-1; Wed, 19 Feb 2025 15:20:42 -0500 X-MC-Unique: oXMtMI1hMOiK1j6B5l87eQ-1 X-Mimecast-MFC-AGG-ID: oXMtMI1hMOiK1j6B5l87eQ_1739996442 Received: by mail-oa1-f69.google.com with SMTP id 586e51a60fabf-2b1aa0c87daso42966fac.1 for ; Wed, 19 Feb 2025 12:20:42 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739996442; x=1740601242; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=m56pAf3/12TQHH7eDD4tbpCjv5t0oQOoxHOFLr4f6XE=; b=ZRAQE8Izhu++fZy1xG9/8Z9ZIWxkV/PssE3Psyh2hBBSMqlwcHsIxa4+iQ31FW8KrZ 2jFRFvtIh2kc3qOCxTZrM1fJeruNcNdioWi+i2iRfy4eHkQIRR+IBoQB1oh3KZ1YjkC5 PhM72FwkhqmGxvWiyuxPgvLsI7qlsqGXsm8tSJV3/fWTiafRSt0qb7jPjiTj3oRdj70t gvPoelszHrLy1MOqe9N0rrpD/YpAN+3w/AUUwQhCbBPhllKWtwsUM25dNAHYos9cFFQL B8HOtUwyHmy716Wo8Is/U0qfxwn/SUlxH2YmtYyZ8g2BSxCsEH5LkzrN1Zv241ZyAnVa TBIQ== X-Forwarded-Encrypted: i=1; AJvYcCVWtoJZGIVt/BUuGNq4KMcqMlKO+LwFjNHSmPAnzE52FjzSNlb20ybIBGU8+bqTsgmRF4Zj3brsadQRA3M=@vger.kernel.org X-Gm-Message-State: AOJu0Yx49VxCzCrmBwWkxX0EimcqmoGjIXPyVqo7qPa5CFy3Tr1+EgcQ Nu2R73PjezDj/TYuwHNo+FRQ11I2RdwrLG3VVAXQKVOdVRflCdAMhnC8Dwelm6ELkWow5WCKlTj lcWQ9bcu7hnqdXec+Turt93L4ikIHljE3unUQjXKc9ux39/kN64Zhe1TkVLnSXA== X-Gm-Gg: ASbGncv+YdBwjAUIaeUQtfgZJeznhdYNSfumTnXLc2Xzm8lhSIBJCutUPv82NBHQso9 /kXSzJigBK1DET9cwbtASJOBy0tRFtvPSg/8VScWA1xVQGK5ORwpSTatbBSI+MICL4T1MqjJFZk Fil5gQFhTdlRq6dhyrqr+OVa6B4gc9vcs4bPjEOQs9+KgRnCXt1BB+LiAmM9nQc+9wbuDd1qNYP uRxrSqzopF9fcaVAewb6bTb5UJBJ2tZhUxJx3reOf1EdpQRJC7beMyPOZY0JDVRw95Csbn7WgL9 4GSL2ZJlLG+hdnfftHxJ/TH/DBw+NuKibD5nHK/1qkosjH3G X-Received: by 2002:a05:6870:4d09:b0:29e:719b:7837 with SMTP id 586e51a60fabf-2bc99aaf44dmr12652944fac.13.1739996441783; Wed, 19 Feb 2025 12:20:41 -0800 (PST) X-Google-Smtp-Source: AGHT+IEOdcXnpAP5VT98wQduj8iHZ9g14YA5f3YWOv7XwDN3ex16h3ex15yOmypTd3pGd+9sLBFq3Q== X-Received: by 2002:a05:6870:4d09:b0:29e:719b:7837 with SMTP id 586e51a60fabf-2bc99aaf44dmr12652925fac.13.1739996441517; Wed, 19 Feb 2025 12:20:41 -0800 (PST) Received: from ?IPV6:2601:188:c100:5710:627d:9ff:fe85:9ade? ([2601:188:c100:5710:627d:9ff:fe85:9ade]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-2bd1d8fb86dsm525430fac.4.2025.02.19.12.20.39 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 19 Feb 2025 12:20:40 -0800 (PST) From: Waiman Long X-Google-Original-From: Waiman Long Message-ID: <8ca57548-4b18-401d-bfda-95bc12216adf@redhat.com> Date: Wed, 19 Feb 2025 15:20:39 -0500 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/2] hung_task: Dump the blocking task stacktrace To: Lance Yang , mhiramat@kernel.org Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , Andrew Morton , Boqun Feng , Joel Granados , Anna Schumaker , Kent Overstreet , Yongliang Gao , Steven Rostedt , Tomasz Figa , Sergey Senozhatsky , linux-kernel@vger.kernel.org, Linux Memory Management List References: <173997003868.2137198.9462617208992136056.stgit@mhiramat.tok.corp.google.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2/19/25 10:02 AM, Lance Yang wrote: > On Wed, Feb 19, 2025 at 9:33 PM Lance Yang wrote: >> CC linux-mm >> >> On Wed, Feb 19, 2025 at 9:00 PM Masami Hiramatsu (Google) >> wrote: >>> Hi, >>> >>> The hung_task detector is very useful for detecting the lockup. >>> However, since it only dumps the blocked (uninterruptible sleep) >>> processes, it is not enough to identify the root cause of that >>> lockup. >>> >>> For example, if a process holds a mutex and sleep an event in >>> interruptible state long time, the other processes will wait on >>> the mutex in uninterruptible state. In this case, the waiter >>> processes are dumped, but the blocker process is not shown >>> because it is sleep in interruptible state. > Cool! I just ran into something similar today, but with rwsem. In that > case, the blocked process was locked up, and we could not identify > the root cause either ;( Once this patch series is settled down, we can extend rwsem to provide similar feature. Cheers, Longman