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=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 443F4C433E0 for ; Fri, 22 Jan 2021 15:12:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D24923AAC for ; Fri, 22 Jan 2021 15:12:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729136AbhAVPJR (ORCPT ); Fri, 22 Jan 2021 10:09:17 -0500 Received: from mail.kernel.org ([198.145.29.99]:40556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729070AbhAVPCz (ORCPT ); Fri, 22 Jan 2021 10:02:55 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8405623ABA; Fri, 22 Jan 2021 15:02:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611327734; bh=ytzMBlkdUUvKuZjby1OfxMsyN3uTMqyGAf4Tx3EsXMw=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=Cxn/UfyTZSBdxJ5NSf27EGBMJrR3fjpYaIxVDhtzPneYa+ovB4Fu5cCxdaBwq+Igz KS/Qg6ieGPx/3iSUfYpBAlkFZG7X9qwTMLH7FdAFPrVzzx5HFRTJZs2yiHa0rkphkh iFXo6dGYof2lUHfqxMCDR0UKSsEXZIfycal3g2iXsO4uShnDVcGafPtMJULzdYB7KT zO/0ZG9qVfgVk7vIUTBNCIjSoUm8xEB4n8dUSlBDfc+U8SDNRieckSjSu4OJ3BytNo nYsr14/tWshCatkMi9coOmZXVCnIBwDTTn/Fi1M+4vczprzsIAVHJmciI/kPJ7zE6d u84Ydz3Pchx/w== Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 504373522649; Fri, 22 Jan 2021 07:02:14 -0800 (PST) Date: Fri, 22 Jan 2021 07:02:14 -0800 From: "Paul E. McKenney" To: Frederic Weisbecker Cc: Peter Zijlstra , LKML , Mel Gorman , Michal Hocko , Thomas Gleixner , Ingo Molnar , Michal Hocko Subject: Re: [RFC PATCH 0/7] preempt: Tune preemption flavour on boot v4 Message-ID: <20210122150214.GD2743@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20210118141223.123667-1-frederic@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210118141223.123667-1-frederic@kernel.org> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 18, 2021 at 03:12:15PM +0100, Frederic Weisbecker wrote: > Hi, > > Here is a new version of the feature that can select the preempt flavour > on boot time. Note that it doesn't entirely mimic the actual real > config-based preemption flavours, because at least preempt-RCU > implementation is there in any case. > > Also there is still some work to do against subsystems that may play > their own games with CONFIG_PREEMPT. > > In this version: > > * Restore the initial simple __static_call_return0() implementation. > > * Uninline __static_call_return0 on all flavours since its address is > always needed on DEFINE_STATIC_CALL() > > * Introduce DEFINE_STATIC_CALL_RET0() > > git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git > preempt/dynamic-v4 > > HEAD: b5f3b1da9df4197d0b0ffe0f55f0f6a8c838d75f I gave these a quick test and got the following: Warning: Kernel ABI header at 'tools/include/linux/static_call_types.h' differs from latest version at 'include/linux/static_call_types.h'. Other than that, looks good. Thanx, Paul > Thanks, > Frederic > --- > > Peter Zijlstra (Intel) (4): > preempt/dynamic: Provide cond_resched() and might_resched() static calls > preempt/dynamic: Provide preempt_schedule[_notrace]() static calls > preempt/dynamic: Provide irqentry_exit_cond_resched() static call > preempt/dynamic: Support dynamic preempt with preempt= boot option > > Peter Zijlstra (2): > static_call/x86: Add __static_call_return0() > static_call: Pull some static_call declarations to the type headers > > Frederic Weisbecker (1): > static_call: Provide DEFINE_STATIC_CALL_RET0() > > Michal Hocko (1): > preempt: Introduce CONFIG_PREEMPT_DYNAMIC > > > Documentation/admin-guide/kernel-parameters.txt | 7 ++ > arch/Kconfig | 9 +++ > arch/x86/Kconfig | 1 + > arch/x86/include/asm/preempt.h | 34 ++++++--- > arch/x86/kernel/static_call.c | 17 ++++- > include/linux/entry-common.h | 4 ++ > include/linux/kernel.h | 23 ++++-- > include/linux/sched.h | 27 ++++++- > include/linux/static_call.h | 43 ++++-------- > include/linux/static_call_types.h | 29 ++++++++ > kernel/Kconfig.preempt | 19 +++++ > kernel/entry/common.c | 10 ++- > kernel/sched/core.c | 93 ++++++++++++++++++++++++- > kernel/static_call.c | 5 ++ > 14 files changed, 271 insertions(+), 50 deletions(-)