From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D3DD61D63E4 for ; Mon, 14 Apr 2025 21:38:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744666685; cv=none; b=gcZ1JbQla4tqeqyhos4RyVG9PFD4BVZlt3vPtV3t8iOW+9MvvKZrQzYzi1AV9oICrJ8jngLrWtBtqwOpJyaU9ljGCodXQK8PpUOMjl8w6/jK8gjA7voGtlootkWuYo+kyTuNz9Evg+eoPMAzg9Am20Nbl3X0YgRqdQfSv6+udgI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744666685; c=relaxed/simple; bh=2k+Q2bMsVBsXMNJejuMjGWROLDWcuJlkfU2MZPNYr40=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=cFXpwzNbC1Y5tXus9oMOeQIWU6POK2kjVmsgiWFFRakhoqF494W1rNg4o0SeDlCOkM4AiZq6gMbxe5/lyokVj8qbw81rw9CAa8b6QeXtWK9ldVOJpTcjdf99hbqrL9OBav6HT+Nlh7Svq5SHWM9N0Es0d9XtB+wcyXiYWlakJmA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=RlqmTAZj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="RlqmTAZj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1604C4CEE2; Mon, 14 Apr 2025 21:38:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1744666685; bh=2k+Q2bMsVBsXMNJejuMjGWROLDWcuJlkfU2MZPNYr40=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=RlqmTAZju2gzfQ42x65PYqWCFH7DqOHgMHTUQ+TqlWMEFdgqe3KnM57ceYVWbs+Kj BAR03j9Ah57/HfDAVBjFiTl3uy2O9bXkEXhk2crr2SiVOv2Asin2uQvCYqciZizm5f NpzZcXpHGhcNYH/K8Mo3I9BWLni4j9gQYEOjADX8= Date: Mon, 14 Apr 2025 14:38:04 -0700 From: Andrew Morton To: Lance Yang Cc: will@kernel.org, peterz@infradead.org, mingo@redhat.com, longman@redhat.com, mhiramat@kernel.org, anna.schumaker@oracle.com, boqun.feng@gmail.com, joel.granados@kernel.org, kent.overstreet@linux.dev, leonylgao@tencent.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, senozhatsky@chromium.org, tfiga@chromium.org, amaindex@outlook.com, jstultz@google.com Subject: Re: [PATCH v5 0/3] hung_task: extend blocking task stacktrace dump to semaphore Message-Id: <20250414143804.e05de499b378f4da4cdc5f59@linux-foundation.org> In-Reply-To: <20250414145945.84916-1-ioworker0@gmail.com> References: <20250414145945.84916-1-ioworker0@gmail.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 14 Apr 2025 22:59:42 +0800 Lance Yang wrote: > Inspired by mutex blocker tracking[1], this patch series extend the > feature to not only dump the blocker task holding a mutex but also to > support semaphores. Unlike mutexes, semaphores lack explicit ownership > tracking, making it challenging to identify the root cause of hangs. To > address this, we introduce a last_holder field to the semaphore structure, > which is updated when a task successfully calls down() and cleared during > up(). Thanks, I'll queue this series in mm.git's mm-nonmm-unstable branch for some test and exposure.