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 33F2810F9; Mon, 25 Nov 2024 03:44:47 +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=1732506288; cv=none; b=QJJNGHQ6rJHMk7bBJEXafPaJMui9GwS7FvwWh/pNWJvlNPQp7y6hwmmYgfvX6XjS2cFq/8rrJMd8ObuXNsD+hpnzhaXfIEAfp3HTtflQOW08YLRY3MNImHc1dzgGALY7bmSWgfjpLjP21aGYDHHSeQSWQJBZFuJWwgu4/LYyDRw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732506288; c=relaxed/simple; bh=ZRnoajD1QdXZX6krqeoKi10PkO2r+xrRVPlVkYB7UZc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=QxTtAnrCdN+O36RryvTM64Y0UHlk5An2BJ1W9Mg9y5pQs5F0oLrIuVXL6RYvwul/BNiThq7B4wfd1f/stMjNcTOl+0vuAJtP/DqQ/cw/KG5Un2czE+DWkZ90bm9g1cnUhS5HIkroJz+bKVgKzPzHAS0tBU5C8MhVznYqMjW7GUA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A050C4CECE; Mon, 25 Nov 2024 03:44:43 +0000 (UTC) Date: Sun, 24 Nov 2024 22:44:41 -0500 From: Steven Rostedt To: Alexei Starovoitov Cc: Peter Zijlstra , Ruan Bonan , "mingo@redhat.com" , "will@kernel.org" , "longman@redhat.com" , "boqun.feng@gmail.com" , "linux-kernel@vger.kernel.org" , "kpsingh@kernel.org" , "mattbobrowski@google.com" , "ast@kernel.org" , "daniel@iogearbox.net" , "andrii@kernel.org" , "martin.lau@linux.dev" , "eddyz87@gmail.com" , "song@kernel.org" , "yonghong.song@linux.dev" , "john.fastabend@gmail.com" , "sdf@fomichev.me" , "haoluo@google.com" , "jolsa@kernel.org" , "mhiramat@kernel.org" , "mathieu.desnoyers@efficios.com" , "bpf@vger.kernel.org" , "linux-trace-kernel@vger.kernel.org" , "netdev@vger.kernel.org" , Fu Yeqi Subject: Re: [BUG] possible deadlock in __schedule (with reproducer available) Message-ID: <20241124224441.5614c15a@rorschach.local.home> In-Reply-To: <20241124223045.4e47e8b7@rorschach.local.home> References: <24481522-69BF-4CE7-A05D-1E7398400D80@u.nus.edu> <20241123202744.GB20633@noisy.programming.kicks-ass.net> <20241123180000.5e219f2e@gandalf.local.home> <20241124223045.4e47e8b7@rorschach.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-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 Sun, 24 Nov 2024 22:30:45 -0500 Steven Rostedt wrote: > > > Ack. BPF should not be causing deadlocks by doing code called from > > > tracepoints. > > > > I sense so much BPF love here that it diminishes the ability to read > > stack traces :) > > You know I love BPF ;-) I do recommend it when I feel it's the right > tool for the job. BTW, I want to apologize if my email sounded like an attack on BPF. That wasn't my intention. It was more about Peter's response being so short, where the submitter may not understand his response. It's not up to Peter to explain himself. As I said, this isn't his problem. I figured I would fill in the gap. As I fear with more people using BPF, when some bug happens when they attach a BPF program somewhere, they then blame the code that they attached to. If this was titled "Possible deadlock when attaching BPF program to scheduler" and was sent to the BPF folks, I would not have any issue with it. But it was sent to the scheduler maintainers. We need to teach people that if a bug happens because they attach a BPF program somewhere, they first notify the BPF folks. Then if it really ends up being a bug where the BPF program was attached, it should be the BPF folks that inform that subsystem maintainers. Not the original submitter. Cheers, -- Steve