From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 42F453CD8BF; Thu, 17 Sep 2026 18:45:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789670741; cv=none; b=Cz39GdhoVmCu//xZybCoknhIko7vE77ICjS6lvEPQn8tejKiaL4O7jiwQK4BvaLMmRx48kfcD471iWDOO5MVWiVCAm0pBpsYyMHdWRxjR80QSK67aCzexXV59WNDd/gIEXzenGoad+uB/Hyv/WMxUfggratY3mUvQQ4jcBfjWl4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789670741; c=relaxed/simple; bh=dGPj631yJf05MB7oAsxBuAZXm3ahp193vFT2rP7+F8Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tdEo1M41tIse2zOGq2z8PK9Xp24WbO9eTiK8+QzOoTxF8gUPyNS4JwQHCh/vBPSJVfljMBmO2VXdELJNgAi88c+QhvW0Ex+frHZiMX9kktwQDY3tjlo4iYmT8+meowiv4GUMAqNTqQc1VyYLt8INDiDH+vAzMYA7P9jUOhJSh7k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=h33H9Gdu; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="h33H9Gdu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43C4C1F00893; Thu, 17 Sep 2026 18:45:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789670740; bh=VUqmoZ9tkjprNUAzv5MpNYkWxkSqU7Rla2JQs5OrKPE=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=h33H9GduZ2Nbb//sSFkLLwqVDqBIdeknn/eumej5e7rnzoQFxi4MlgOnM2Gt6j7GB iE3tvUHRv+ixjLq+DWgWPyT7DoF/CYAC3R4euNtsJ2N4LHOUWTuAenMrDCqNT8k0zG U59UbDrs8tfw88NjPBWxAmzoXD7fWC5AStfO6GkpqIyMxP60IaZf1VURFo7L1a2N31 CZ97fG48sVdVZAt67BzNGDjQ2uyRlnAdjFzsJJASWRSNkAFHDnymfoO1wKmIi3sYQ/ uiC5mOc8yyM/Z/8oOa/Nnm/1UaEfhLKvQNS2zEGERuhrZ7oxaz7OX2ScghU6oH5ZC+ c1PYnG1LmvA9g== Date: Thu, 17 Sep 2026 20:45:36 +0200 From: Frederic Weisbecker To: "Paul E. McKenney" Cc: Josef Bacik , Neeraj Upadhyay , Joel Fernandes , Boqun Feng , Thomas Gleixner , Peter Zijlstra , Steven Rostedt , Masami Hiramatsu , Mark Rutland , Jiri Olsa , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , x86@kernel.org, Catalin Marinas , Will Deacon , Puranjay Mohan , Xu Kuohai , Andy Lutomirski , Josh Triplett , Uladzislau Rezki , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Juergen Gross , Luis Chamberlain , Ihor Solodrai , linux-kernel@vger.kernel.org, rcu@vger.kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, xen-devel@lists.xenproject.org Subject: Re: [PATCH RFC v3 03/13] rcu-tasks: Add a Tasks RCU implementation for reader-marked trampolines Message-ID: References: <91687748-0781-4133-baed-43cf82f35ff5@paulmck-laptop> <6afb0afe-e7b8-46b4-9fea-2c7cf4791044@paulmck-laptop> <8b73e1b3-0580-4ba9-b2e0-6363e429808d@paulmck-laptop> <8fea176a-0ca0-4a70-8cf9-8240a22359e4@paulmck-laptop> 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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <8fea176a-0ca0-4a70-8cf9-8240a22359e4@paulmck-laptop> Le Thu, Sep 17, 2026 at 08:40:10AM -0700, Paul E. McKenney a écrit : > > > Trampolines that transfer control to tracing code could supply the needed > > > cleanup call. But last I checked, there were trampolines that transferred > > > directly back to the original code, with no opportunity for cleaning up. > > > > > > Or am I still missing a trick here? > > > > You're right. So we'll indeed need to reuse the deferred qs points here. > > Except this is getting a bit involved. > > Don't get me wrong, if Josef is happy to take this on, far be it from me > to stand in his way. But if not, we should be willing to treat this > optimization as a follow-on effort, whether by Josef or someone else. Sure, I guess I can try the follow-on, especially if it leads to removing all this RCU tasks black magic. Thanks. -- Frederic Weisbecker SUSE Labs