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 E1A9FC433DF for ; Tue, 7 Jul 2020 01:33:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB1BC206E6 for ; Tue, 7 Jul 2020 01:33:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594085616; bh=0Y0CXgWgIGOuqURmwOT7L3TTrVG7g4ZNpBp5WtkSiLg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=K8+LdzmYZAbgiu0HWNSViFEy28NbP6ANAutS6IdvKA1H7xZOU/wWyoAyQU2koONLM /0VqqlxoNy1K9DctGt/wYdioy1RKE9JliEkwqZhs+MveaVU7wMuLpAD+O/yX/m8Ea9 F7QOjd2lDBKlg97tK354Herwvdp5bPtWpol8d0Ss= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728152AbgGGBdg (ORCPT ); Mon, 6 Jul 2020 21:33:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:38680 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727951AbgGGBdN (ORCPT ); Mon, 6 Jul 2020 21:33:13 -0400 Received: from lenoir.home (lfbn-ncy-1-317-216.w83-196.abo.wanadoo.fr [83.196.152.216]) (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 4F35220719; Tue, 7 Jul 2020 01:33:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594085592; bh=0Y0CXgWgIGOuqURmwOT7L3TTrVG7g4ZNpBp5WtkSiLg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BLxw8cBFpzRywhX+mElFUlxLGAkfIPEkqJfhWc24QuS79dsMUuMu70WhrEAgHoFiw L/tYtqkn1EDSWXfAwNCjlm7ShIGNh4MVzyAAhuLILfhxZ76kygYS/p2oCoXjYfDWMu QtomQElslQ105vgjJ/XXYOyvlbM7TNrXoUXFgxNE= From: Frederic Weisbecker To: Thomas Gleixner Cc: LKML , Frederic Weisbecker , Anna-Maria Gleixner , Peter Zijlstra , Juri Lelli Subject: [PATCH 4/9] timers: Always keep track of next expiry Date: Tue, 7 Jul 2020 03:32:48 +0200 Message-Id: <20200707013253.26770-5-frederic@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200707013253.26770-1-frederic@kernel.org> References: <20200707013253.26770-1-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 | 36 +++++++++++++++++++----------------- 1 file changed, 19 insertions(+), 17 deletions(-) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index acf7cb8c09f8..8a4138e47aa4 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -558,8 +558,22 @@ 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)) @@ -578,21 +592,7 @@ 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); } @@ -1490,7 +1490,6 @@ 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 @@ -1582,6 +1581,7 @@ 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: @@ -1787,6 +1787,7 @@ 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); @@ -2039,6 +2040,7 @@ static void __init init_timer_cpu(int cpu) base->cpu = cpu; raw_spin_lock_init(&base->lock); base->clk = jiffies; + base->next_expiry = base->clk + NEXT_TIMER_MAX_DELTA; timer_base_init_expiry_lock(base); } } -- 2.26.2