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 8E568C433DF for ; Wed, 1 Jul 2020 01:10:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A65120771 for ; Wed, 1 Jul 2020 01:10:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593565849; bh=aKRhwVhN7D8SHkrFiRvmf9rY8fNYZH19eSfLROUGcbo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LuPN/0/bOaFIREtdscRYn5DDAXMogTgivoS03BgV1i/OgE6c01q1HP2QuEeNcBmSF WVGSk/A6/duBDv9xwFTi3liQUXqq6yrYbY4588M5QR+IHSLmlbcswX+3VI7hsmkB/g d/wLrBfnV/G9N4cTRZ259T+7ADTvicKRMFtkwi88= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726733AbgGABKs (ORCPT ); Tue, 30 Jun 2020 21:10:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:57032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726562AbgGABKo (ORCPT ); Tue, 30 Jun 2020 21:10:44 -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 D219E20771; Wed, 1 Jul 2020 01:10:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593565844; bh=aKRhwVhN7D8SHkrFiRvmf9rY8fNYZH19eSfLROUGcbo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=09UUC61gkhq5rEKjTfs+RwysTLq4sInzpV11pLSKNJulkblx0pDm4w6m22QTlhOR0 GgZu7+4YbRyhtHD4a0y6LYoRMtJJe5D10FBS3NjK9lFo+UHKAE0Vu1wIxzNNfoxoAU tTM5V1QG4V5RUoBXWDpsfW5IofMVL0So0RTEZzI4= From: Frederic Weisbecker To: Thomas Gleixner Cc: LKML , Frederic Weisbecker , Anna-Maria Gleixner , Peter Zijlstra , Juri Lelli Subject: [RFC PATCH 05/10] timers: Always keep track of next expiry Date: Wed, 1 Jul 2020 03:10:25 +0200 Message-Id: <20200701011030.14324-6-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 So far next expiry was only tracked while the CPU was in nohz_idle mode in order to cope with missing ticks that can't increment the base->clk periodically anymore. We are going to expand that logic beyond nohz in order to spare timers softirqs so do it unconditionally. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Anna-Maria Gleixner Cc: Juri Lelli --- kernel/time/timer.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 4aa74aafdd33..30f491ec875a 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -550,8 +550,22 @@ trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer) * timer is not deferrable. If the other CPU is on the way to idle * then it can't set base->is_idle as we hold the base lock: */ - if (!base->is_idle) - return; + if (base->is_idle) + wake_up_nohz_cpu(base->cpu); +} + +/* + * Enqueue the timer into the hash bucket, mark it pending in + * the bitmap and store the index in the timer flags. + */ +static void enqueue_timer(struct timer_base *base, struct timer_list *timer, + unsigned int idx) +{ + hlist_add_head(&timer->entry, base->vectors + idx); + __set_bit(idx, base->pending_map); + timer_set_idx(timer, idx); + + trace_timer_start(timer, timer->expires, timer->flags); /* Check whether this is the new first expiring timer: */ if (time_after_eq(timer->expires, base->next_expiry)) @@ -570,21 +584,7 @@ trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer) } else { base->next_expiry = timer->expires; } - wake_up_nohz_cpu(base->cpu); -} -/* - * Enqueue the timer into the hash bucket, mark it pending in - * the bitmap and store the index in the timer flags. - */ -static void enqueue_timer(struct timer_base *base, struct timer_list *timer, - unsigned int idx) -{ - hlist_add_head(&timer->entry, base->vectors + idx); - __set_bit(idx, base->pending_map); - timer_set_idx(timer, idx); - - trace_timer_start(timer, timer->expires, timer->flags); trigger_dyntick_cpu(base, timer); } @@ -1482,7 +1482,6 @@ static int __collect_expired_timers(struct timer_base *base, return levels; } -#ifdef CONFIG_NO_HZ_COMMON /* * Find the next pending bucket of a level. Search from level start (@offset) * + @clk upwards and if nothing there, search from start of the level @@ -1574,6 +1573,7 @@ static unsigned long __next_timer_interrupt(struct timer_base *base) return next; } +#ifdef CONFIG_NO_HZ_COMMON /* * Check, if the next hrtimer event is before the next timer wheel * event: @@ -1779,6 +1779,7 @@ static inline void __run_timers(struct timer_base *base) levels = collect_expired_timers(base, heads); base->clk++; + base->next_expiry = __next_timer_interrupt(base); while (levels--) expire_timers(base, heads + levels); -- 2.26.2