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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68931C55179 for ; Tue, 3 Nov 2020 14:58:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 261CA20757 for ; Tue, 3 Nov 2020 14:58:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="vjbyIUfH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728214AbgKCO62 (ORCPT ); Tue, 3 Nov 2020 09:58:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728065AbgKCO4x (ORCPT ); Tue, 3 Nov 2020 09:56:53 -0500 Received: from mail-qv1-xf43.google.com (mail-qv1-xf43.google.com [IPv6:2607:f8b0:4864:20::f43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 374D7C0613D1 for ; Tue, 3 Nov 2020 06:56:53 -0800 (PST) Received: by mail-qv1-xf43.google.com with SMTP id s1so7818515qvm.13 for ; Tue, 03 Nov 2020 06:56:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=yYv8SzeXH9sTex0t/oRWNoHgyhhHpDNOQ4Uo+mWi1jc=; b=vjbyIUfHDeeytDwg7aODBT1BcbVT18wVvaazIoQfCN/hHJj9ibtSmyeZ31i+Lha9aJ QVpDv9sUHKByvNdl+r4gpaXQHYauF2EEms7PKaYcRnAh+LFoHruzLFi8eEPnu2OhiAUo FjVxfEVnnYi92HGiUg3+kdbw/Ck6smrgNdRpY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=yYv8SzeXH9sTex0t/oRWNoHgyhhHpDNOQ4Uo+mWi1jc=; b=Q7XRdC73aJP6j6IPRUUv9a3P0EhR58NWODM7WfUP5gw85IRC8ktRii/Hd4YrKWcyWb DsXWQ150BlAqe8CNCkQbSnR5J/ZPckGU0mkQlCNUs6hqpDerlww+Y+UcoIgw9FwOs0Ir aZEg4ufeb+j4MoN+T6YD4eRy7vCtvQf2Q/c0M3Wf6bghqlr1zLOwRSuW0rkpcN3ASHQw Zk/aOmA7BhPXMRvgvgX/BIKgCo5otzZIMGdBmMoOLffMiAQslnOe/mTsgVcC+rj4E/6W 0CBjdEjo5aM1pFB00ZW2MdkbX4w2EKlYxgiPTRYuMyRWuIHxo3fBu6dBuXTq5mjMhXCd 9ZPg== X-Gm-Message-State: AOAM533FrAgUuEhJ3mEGAx+k110MacrujYYzv/n8tOGDtRU10w8Ztao3 CmBgoJBj9fUK9Sp2pPUvGOTg6+q/r5xqVQ== X-Google-Smtp-Source: ABdhPJzlobLYzUix2OUj3ncE0UnNkquvmZvj3PWMrzaFKHyR87dV0gs1iLUi7GMioMNq5yH23FLH9g== X-Received: by 2002:a0c:ecc8:: with SMTP id o8mr26872223qvq.54.1604415412463; Tue, 03 Nov 2020 06:56:52 -0800 (PST) Received: from localhost ([2620:15c:6:411:cad3:ffff:feb3:bd59]) by smtp.gmail.com with ESMTPSA id t70sm10299175qke.119.2020.11.03.06.56.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Nov 2020 06:56:51 -0800 (PST) Date: Tue, 3 Nov 2020 09:56:51 -0500 From: Joel Fernandes To: Frederic Weisbecker Cc: linux-kernel@vger.kernel.org, Josh Triplett , Lai Jiangshan , Marco Elver , Mathieu Desnoyers , "Paul E. McKenney" , rcu@vger.kernel.org, Steven Rostedt , "Uladzislau Rezki (Sony)" , fweisbec@gmail.com, neeraj.iitr10@gmail.com Subject: Re: [PATCH v9 3/7] srcu: Fix invoke_rcu_callbacks() segcb length adjustment Message-ID: <20201103145651.GA1304393@google.com> References: <20201103142603.1302207-1-joel@joelfernandes.org> <20201103142603.1302207-4-joel@joelfernandes.org> <20201103144714.GA432431@lothringen> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201103144714.GA432431@lothringen> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 03, 2020 at 03:47:14PM +0100, Frederic Weisbecker wrote: > On Tue, Nov 03, 2020 at 09:25:59AM -0500, Joel Fernandes (Google) wrote: > > With earlier patches, the negative counting of the unsegmented list > > cannot be used to adjust the segmented one. To fix this, sample the > > unsegmented length in advance, and use it after CB execution to adjust > > the segmented list's length. > > > > Reviewed-by: Frederic Weisbecker > > Suggested-by: Frederic Weisbecker > > Signed-off-by: Joel Fernandes (Google) > > This breaks bisection, you need to either fix up the previous patch > by adding this diff inside or better yet: expand what you did > in "rcu/tree: Make rcu_do_batch count how many callbacks were executed" > to also handle srcu before introducing the segcb count. Right, the latter is better. Let us do that. thanks, - Joel