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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 3EDF7C433E0 for ; Wed, 1 Jul 2020 01:11:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13A3E20780 for ; Wed, 1 Jul 2020 01:11:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593565868; bh=LV7P23B00+S8ImLTPp+ijLF3+cQPf7ovG23sO3ILZA8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=QOpQVUHIPCBUI+tqYaObGW3ZbEUK/DEc5hUMMbey0RK//Y7JJGgAyKuBVYKUmoxtv GEPJDloGUprxfD4pyOaANekxRj8+LwfJy/UKuVE7Q7zFEmibjjyW+F3xxAh/AhtOWN owxDkQ//kvS8Kq1VrWv/Qjp5Z220+wtoiv+hc9vM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726871AbgGABLH (ORCPT ); Tue, 30 Jun 2020 21:11:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:57050 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726555AbgGABKq (ORCPT ); Tue, 30 Jun 2020 21:10:46 -0400 Received: from lenoir.home (lfbn-ncy-1-996-218.w90-101.abo.wanadoo.fr [90.101.73.218]) (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 6A47D20781; Wed, 1 Jul 2020 01:10:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593565845; bh=LV7P23B00+S8ImLTPp+ijLF3+cQPf7ovG23sO3ILZA8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jScekagbnRJlFZeSkgNby0+kJKvLj7lTuyCNCNQexmktTGPBvKSVygsaeUfC+Km18 A6aOh3qo9M+7unA2dOm4u93xMqA0SG2GXFs9KNk5Tx2upNPjyAq8tGHFF/LJajwrA+ 2YhAK2J/5dI3jHybc3YVIhwmw0hVlZvAVLzU2SuE= From: Frederic Weisbecker To: Thomas Gleixner Cc: LKML , Frederic Weisbecker , Anna-Maria Gleixner , Peter Zijlstra , Juri Lelli Subject: [RFC PATCH 06/10] timer: Reuse next expiry cache after nohz exit Date: Wed, 1 Jul 2020 03:10:26 +0200 Message-Id: <20200701011030.14324-7-frederic@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200701011030.14324-1-frederic@kernel.org> References: <20200701011030.14324-1-frederic@kernel.org> 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 Now that we track the next expiry unconditionally when a timer is added, we can reuse that information on a tick firing after exiting nohz. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Anna-Maria Gleixner Cc: Juri Lelli --- kernel/time/timer.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 30f491ec875a..4612d26fd09a 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1697,13 +1697,11 @@ static int collect_expired_timers(struct timer_base *base, * the next expiring timer. */ if ((long)(now - base->clk) > 2) { - unsigned long next = __next_timer_interrupt(base); - /* * If the next timer is ahead of time forward to current * jiffies, otherwise forward to the next expiry time: */ - if (time_after(next, now)) { + if (time_after(base->next_expiry, now)) { /* * The call site will increment base->clk and then * terminate the expiry loop immediately. @@ -1711,7 +1709,7 @@ static int collect_expired_timers(struct timer_base *base, base->clk = now; return 0; } - base->clk = next; + base->clk = base->next_expiry; } return __collect_expired_timers(base, heads); } -- 2.26.2