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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7477DC88E72 for ; Thu, 17 Sep 2026 19:34:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=VUqmoZ9tkjprNUAzv5MpNYkWxkSqU7Rla2JQs5OrKPE=; b=1zkTbZt8Db+pHveAUrDGLgeCaD 1RDSGHJvJ/HKwIawxRGt+OLCbu3nx/F9fw0ZXNQHcQeSpA8LJcVjX5+KI7IhtY7arZN1D1pVjqoxj Km3Bv0wRcAX4BkBpEeergsZ5pP8d7IqtShy4kta2mLCAt3HAc+U/oMIC9l6yLzIpDwzqTkQHfFEiQ Uo3XQHiYieJRKt96OhmmO78lis25S8+lVm0w4Y+rMamlIw9eCAIzc8vsuuTdeCFii4vKz2wCyOMsn /C+pj846l/XHtMyx/tUAT1j7UHqMgG3ITu2kdCgMDhJwLawEP7lpMb15719VWCpGFpcOUeOKo399u aZHkTDLg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x7H77-0000000CGw8-2Lep; Thu, 17 Sep 2026 18:45:41 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x7H76-0000000CGw2-1vTZ for linux-arm-kernel@lists.infradead.org; Thu, 17 Sep 2026 18:45:40 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 2340643DF2; Thu, 17 Sep 2026 18:45:40 +0000 (UTC) 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> 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> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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