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 4CD75C433EF for ; Mon, 6 Sep 2021 01:32:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37D9560F43 for ; Mon, 6 Sep 2021 01:32:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239942AbhIFBdi (ORCPT ); Sun, 5 Sep 2021 21:33:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:48676 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345218AbhIFB3y (ORCPT ); Sun, 5 Sep 2021 21:29:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7579D611CC; Mon, 6 Sep 2021 01:23:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1630891413; bh=YcuAE+zGNjEpbYtV8qs07F+5J1E2nWT+L99bwhXST28=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VZTSHR1ARlK3hm3Mj8pPP1Ly64OWfezfok9ywWOJRwW8gb8QtUWLqypRLRW9zq3ou deY3AM66ziNIPhCDV1CcN543YDhjAD0gzOkMOGSB7ci0B+eZKG8fwvx3/mFhGD2heq lcipVSiXAPc+JA0tAf2wuwjgzAckyTH4H2m/Hiu54Xq79cVAZyPzlnamg7TU2/BYWc znrSDzTkVGFN8jGDVakbpgSImVMGXeCeVz2jDIhulhb71gcArnDWAsJabP84vpVDdt aAGKb/S0pgK5vb+0r2K3t8Vl0v56k/dUb0JjgT+GaRPoRkwL3vyEkQP9cBSQ37ApJD D4fa7T7luJ8tw== 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 4.19 08/23] posix-cpu-timers: Force next expiration recalc after itimer reset Date: Sun, 5 Sep 2021 21:23:07 -0400 Message-Id: <20210906012322.930668-8-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210906012322.930668-1-sashal@kernel.org> References: <20210906012322.930668-1-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 bfaa44a80c03..d9feac7aad52 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -1230,8 +1230,6 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, } } - if (!*newval) - return; *newval += now; } -- 2.30.2