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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 42EA3C4332F for ; Mon, 13 Sep 2021 13:30:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3259561507 for ; Mon, 13 Sep 2021 13:30:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239065AbhIMNbV (ORCPT ); Mon, 13 Sep 2021 09:31:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:35044 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240132AbhIMNT4 (ORCPT ); Mon, 13 Sep 2021 09:19:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 76696610FE; Mon, 13 Sep 2021 13:17:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631539063; bh=dd0+vEyGnn4ll4F9/tTk78sT6GA7/5zJigxaZ8m1hmM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MaENfQJllYIeDpiYz1bnHiWafU1ywsOK6tRNmsts7IeAw6pEaoEzhMjs9/2VEoNp8 lBvqmO5wdufGj2eMJZDoyhIduRAM1oTsvYwYFiEOckgT1zmlj83M+CG9aKJQNJIQDs UXaiPFuLakPAlk/abCZGUWK73etAOFHMLtil++m8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Frederic Weisbecker , Thomas Gleixner , "Peter Zijlstra (Intel)" , Sasha Levin Subject: [PATCH 5.4 009/144] posix-cpu-timers: Force next expiration recalc after itimer reset Date: Mon, 13 Sep 2021 15:13:10 +0200 Message-Id: <20210913131048.279520152@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210913131047.974309396@linuxfoundation.org> References: <20210913131047.974309396@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Frederic Weisbecker [ Upstream commit 406dd42bd1ba0c01babf9cde169bb319e52f6147 ] When an itimer deactivates a previously armed expiration, it simply doesn't do anything. As a result the process wide cputime counter keeps running and the tick dependency stays set until it reaches the old ghost expiration value. This can be reproduced with the following snippet: void trigger_process_counter(void) { struct itimerval n = {}; n.it_value.tv_sec = 100; setitimer(ITIMER_VIRTUAL, &n, NULL); n.it_value.tv_sec = 0; setitimer(ITIMER_VIRTUAL, &n, NULL); } Fix this with resetting the relevant base expiration. This is similar to disarming a timer. Signed-off-by: Frederic Weisbecker Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20210726125513.271824-4-frederic@kernel.org Signed-off-by: Sasha Levin --- kernel/time/posix-cpu-timers.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index eacb0ca30193..30e061b210b7 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -1201,8 +1201,6 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clkid, } } - if (!*newval) - return; *newval += now; } -- 2.30.2