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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 4D028C2BA83 for ; Fri, 14 Feb 2020 15:26:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 266D2217F4 for ; Fri, 14 Feb 2020 15:26:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581693986; bh=cI43QToW0rheWH4+4zHAIgLsrAKOLZHrFyGcS2/lDds=; h=From:To:Cc:Subject:Date:List-ID:From; b=XO7/J1VEN7phSe2FirtzPodVw+SnF52prg4PtpdC+lDcnJ2vHTD7hBMmANvUQ5It2 djpwiyhYyEuhbYsnQ/dzA1JgmzKVF6lPXydfJcs7wlvcIu3lSmxGu+UzXf2nfvQd9L LZ1Wka1vhSDHqZKzS9Lqzj0h/08yUwKS/Fw2j0UI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729573AbgBNP0Z (ORCPT ); Fri, 14 Feb 2020 10:26:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:38018 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729412AbgBNP0Z (ORCPT ); Fri, 14 Feb 2020 10:26:25 -0500 Received: from lenoir.home (lfbn-ncy-1-985-231.w90-101.abo.wanadoo.fr [90.101.63.231]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8A1C52168B; Fri, 14 Feb 2020 15:26:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581693984; bh=cI43QToW0rheWH4+4zHAIgLsrAKOLZHrFyGcS2/lDds=; h=From:To:Cc:Subject:Date:From; b=O7jHVBI6xRY4D8Ul0sNkQJPtfqqN/WJakl5yeHEQIgVjXoxWHbgD5Bktu6/in7aLi gR3qEBHLJvf/dxZBifbb8g45JNCBEuqP7zmsUmx7odtAxBYj+U3KlQjDE1RP5a0n00 JlgfEFtVHDL/CFv9MfvzsnDk0bpAfdUpznBbzCec= From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Paul Burton , Peter Zijlstra , "David S . Miller" , Borislav Petkov , Benjamin Herrenschmidt , Paul Mackerras , Thomas Gleixner , Andy Lutomirski , Ralf Baechle , Ingo Molnar , Will Deacon , Catalin Marinas , Michael Ellerman , Russell King Subject: [PATCH 0/5] context_tracking: Remove TIF_NOHZ from 3 archs Date: Fri, 14 Feb 2020 16:26:10 +0100 Message-Id: <20200214152615.25447-1-frederic@kernel.org> X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org TIF_NOHZ is getting deprecated by static keys which avoid to invoke syscall slow path on every syscall. So remove that flag from architectures that don't need it anymore (or worse yet: that spuriously triggered syscall slow path when it's not needed anymore). We hope to remove TIF_NOHZ entirely in the long run (PPC, MIPS, SPARC). If we want to be able to enable/disable nohz full dynamically on runtime, freezing all tasks and iterating through the whole tasklist to set/clear TIF_NOHZ doesn't sound very appealing. git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git arch/nohz WARNING: untested on ARM 32 HEAD: 92502ebbf06ac37858694ed8f9d16fdb13ed0fe3 Thanks, Frederic --- Frederic Weisbecker (4): context-tracking: Introduce CONFIG_HAVE_TIF_NOHZ x86: Remove TIF_NOHZ arm: Remove TIF_NOHZ arm64: Remove TIF_NOHZ Thomas Gleixner (1): x86/entry: Remove _TIF_NOHZ from _TIF_WORK_SYSCALL_ENTRY arch/Kconfig | 16 +++++++++++----- arch/arm/include/asm/thread_info.h | 1 - arch/arm64/include/asm/thread_info.h | 4 +--- arch/mips/Kconfig | 1 + arch/powerpc/Kconfig | 1 + arch/sparc/Kconfig | 1 + arch/x86/include/asm/thread_info.h | 10 ++-------- kernel/context_tracking.c | 2 ++ 8 files changed, 19 insertions(+), 17 deletions(-)