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=-19.4 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_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 D8FDCC07E94 for ; Fri, 4 Jun 2021 11:32:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0953613FF for ; Fri, 4 Jun 2021 11:32:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230034AbhFDLdv (ORCPT ); Fri, 4 Jun 2021 07:33:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:34240 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229740AbhFDLdu (ORCPT ); Fri, 4 Jun 2021 07:33:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4A839613F9; Fri, 4 Jun 2021 11:32:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622806324; bh=HBQeEl/CUgi+q6JezbobhTZCvfu9mgxmoaahKITVgPQ=; h=From:To:Cc:Subject:Date:From; b=LBUxY5BpUKhPrEgSAYTDfML8Y2JaVbPPeF/f6lpCOStOUQfmoe+vfBVkC03Qn927K 6xei27p1wkZ84eDYGFfnYKfnjEAGlq4pfpaAdW27UruWgpIY+jrHQk2CkoImnIFNNI kg4479S83pvscF4Dq4+NccM77ZAAh3PHFbiIczkXkOeCD5QNtyRahwkdiDvy8QJ/PL VfCmUV89hh80Ut5W2jXMMzLZqX6R1GwJqvuCqNWBrB3UAL+Xfi6jh3PZ3tJFwqwoIc BkIMyL2+xW7uleVKQyZvnxa32fm/PwcLyq7eVKd1zny2ZQxmyPpsN+tMrttCE2IQ4q 90zEIK9GHvOng== From: Frederic Weisbecker To: Thomas Gleixner Cc: LKML , Frederic Weisbecker , Peter Zijlstra , "Eric W . Biederman" , Oleg Nesterov , Ingo Molnar Subject: [PATCH 0/6] posix-cpu-timers: Bunch of fixes Date: Fri, 4 Jun 2021 13:31:53 +0200 Message-Id: <20210604113159.26177-1-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The first is a race due to locklessly starting process wide cputime counting. The others stop the process wide cputime counting and tick dependency when they are not necessary anymore. Note I don't really like patch 5/6 and in fact I hope we could manage to remove this early inline cpu_timer_fire() call from timer_settime(). All we get from it is headaches. Besides, the handler isn't invoked from the actual target and that doesn't sound ideal. git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git timers/urgent HEAD: f8f908c9d2b2f1e100cd549206c95a4e65e5f023 Thanks, Frederic --- Frederic Weisbecker (6): posix-cpu-timers: Fix rearm racing against process tick posix-cpu-timers: Don't start process wide cputime counter if timer is disabled posix-cpu-timers: Force next_expiration recalc after timer deletion posix-cpu-timers: Force next_expiration recalc after timer reset posix-cpu-timers: Force next expiration recalc after early timer firing posix-cpu-timers: Force next expiration recalc after itimer reset include/linux/posix-timers.h | 11 ++++- kernel/time/posix-cpu-timers.c | 97 +++++++++++++++++++++++++++++++++--------- 2 files changed, 87 insertions(+), 21 deletions(-)