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_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 E1FBBC282C8 for ; Mon, 6 Sep 2021 01:36:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCA6F60EE6 for ; Mon, 6 Sep 2021 01:36:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352877AbhIFBfj (ORCPT ); Sun, 5 Sep 2021 21:35:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:48340 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351773AbhIFBbC (ORCPT ); Sun, 5 Sep 2021 21:31:02 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C7F4861242; Mon, 6 Sep 2021 01:24:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1630891462; bh=/fkWzKP+GxVrk1Zm0EnzbVWiy1P+JhIx0aCKX8WoaJM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AZ1UvuZEomgWxRFYm6Oj4sTAKuRMj1Mkr/Lim8lYSG8apzZf00O8o2rey0niSX9wh kglfOpAwwnmfQ5afgMYjusLKUGAA4rp5zLIqysRSAH54jSlpXBmacpVYwiXqjearNL avSM/tEO/SDBGN5FPbsENV277WT8DwPFQabAHkUCLUSBOgejLOX8CArQwY8pGGNM+4 h6lPCo2bie/2yISgntGOo1wSYxcpvuJR92+tm7OWnbCa3R0N+T9PFwtKZscoYVseaJ rn770MMkB77OL0MOMG9HrNnyioP110g97rbKUnX35Me4O3EE95drjZMLcAe9HYvKHL 6BvgMhKhWyZvg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Frederic Weisbecker , Thomas Gleixner , Peter Zijlstra , Sasha Levin Subject: [PATCH AUTOSEL 4.9 05/14] posix-cpu-timers: Force next expiration recalc after itimer reset Date: Sun, 5 Sep 2021 21:24:06 -0400 Message-Id: <20210906012415.931147-5-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210906012415.931147-1-sashal@kernel.org> References: <20210906012415.931147-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 9fff077d0ffc..458ffe4ac6fb 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -1240,8 +1240,6 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, } } - if (!*newval) - return; *newval += now; } -- 2.30.2