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=-7.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 1DB90C433E0 for ; Thu, 21 Jan 2021 21:44:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB3BD23A5C for ; Thu, 21 Jan 2021 21:44:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726663AbhAUVnI (ORCPT ); Thu, 21 Jan 2021 16:43:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:39862 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727651AbhAUVjy (ORCPT ); Thu, 21 Jan 2021 16:39:54 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7C28A206BE; Thu, 21 Jan 2021 21:39:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611265153; bh=aLuf1i9OQEMa2qBpCs/Nu07vuKtAWu6kZISwL4/LvOw=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=p4KSYU373sYoPwYkPjI/RoAXpn44Un2Dfhs5PP8/rYka97g6UN6v7q2ilehqFDUfq rJdgMZPx4ZxXALWhLNcOx2ymd7DXvwKcPNLIsttHJJaBDWrXen8e0Dh66ARS5OLyi2 VUjq6cFhrXFeZ1icra2T6Bz1Cu2baUOUlHF5LUtcbSj5BuuWPy3CmykYheIkP/2u9W SO7z3lE3BUc7g4d1l4HAL//gSdeiK6l7gt6JnSgvgexEmgh9+BORxTtVHlJ/0KeAMp FmYlD21fe2jVC9neX0/JtGZqHk2/i9ZBNsj3QUmMRWqf3yzF3QaoExYEpNXmp8g0mA BX6GYAjzvWdVQ== Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 4840F35226D8; Thu, 21 Jan 2021 13:39:13 -0800 (PST) Date: Thu, 21 Jan 2021 13:39:13 -0800 From: "Paul E. McKenney" To: Yury Norov Cc: Linux Kernel Mailing List , Peter Zijlstra , Paul Gortmaker , kernel-team@fb.com, Andrew Morton Subject: Re: [PATCH RFC cpumask] Allow "all", "none", and "last" in cpumask strings Message-ID: <20210121213913.GA19646@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20210106004850.GA11682@paulmck-ThinkPad-P72> <20210121165725.GP2743@paulmck-ThinkPad-P72> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210121165725.GP2743@paulmck-ThinkPad-P72> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 21, 2021 at 08:57:25AM -0800, Paul E. McKenney wrote: > On Wed, Jan 20, 2021 at 11:11:48PM -0800, Yury Norov wrote: > > On Wed, Jan 6, 2021 at 12:49 AM Yury Norov wrote: > > > > > > On Tue, Jan 5, 2021 at 4:48 PM Paul E. McKenney wrote: > > > > > > > > Hello! > > > > > > > > This series allows "all", "none", and "last" to be used in cpumask > > > > strings. This allows these strings to be less dependent on the underlying > > > > system. For example, currently a string specifying all but the first > > > > CPU must be "1-7" on an eight-CPU system and "1-15" on a 16-CPU system. > > > > With this series, the single string "1-last" can be used regardless of the > > > > number of CPUs (at least assuming that each system has at least one CPU). > > > > > > 'none' may be implemented as an empty string or string with separators only, > > > but I have nothing against explicit 'none'. See other comments inline. > > > > > > Thanks, > > > Yury. > > > > > > > 1. Un-inline cpulist_parse for SMP; prepare for ascii helpers, > > > > courtesy of Paul Gortmaker. > > > > > > > > 2. Make "all" alias global and not just RCU, courtesy of Paul > > > > Gortmaker. > > > > > > > > 3. Add a "none" alias to complement "all", courtesy of Paul > > > > Gortmaker. > > > > > > > > 4. Add "last" alias for cpu list specifications, courtesy of Paul > > > > Gortmaker. > > > > > > > > 5. Use "all" and "last" in "nohz_full" and "rcu_nocbs". > > > > > > > > Thanx, Paul > > > > Hi Paul, > > > > Today I found this series in linux-next despite downsides discovered during > > the review. This series introduces absolutely unneeded cap on the number of > > cpus in the system (9999), and also adds unsafe and non-optimal code. > > > > In addition to that, I observe this warning on powerpc: > > CC lib/cpumask.o > > lib/cpumask.c: In function ‘cpulist_parse’: > > lib/cpumask.c:222:17: warning: cast from pointer to integer of > > different size [-Wpointer-to-int-cast] > > 222 | memblock_free((phys_addr_t)cpulist, len); > > | ^ > > > > Can you please revert this series unless all the problems will be fixed? > > Thank you for your further review and comments! > > I had been keeping the old series as a placeholder for its anticipated > replacement, but given the compiler warning you note above and given > that it is getting uncomfortably close to the time when I send my pull > request, I will remove it from the -rcu rcu/next branch sourced by -next. Except that the resulting rebasing and testing took too long, so there will be one more -next with these commits. Thanx, Paul