From patchwork Wed Apr 4 08:45:39 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 10322271 X-Patchwork-Delegate: rjw@sisk.pl Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9EB5B602C8 for ; Wed, 4 Apr 2018 08:56:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8F6B628815 for ; Wed, 4 Apr 2018 08:56:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 83A3828E18; Wed, 4 Apr 2018 08:56:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 20E1328867 for ; Wed, 4 Apr 2018 08:56:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751155AbeDDIze (ORCPT ); Wed, 4 Apr 2018 04:55:34 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:55147 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751339AbeDDIxE (ORCPT ); Wed, 4 Apr 2018 04:53:04 -0400 Received: from 79.184.255.92.ipv4.supernova.orange.pl (79.184.255.92) (HELO aspire.rjw.lan) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83) id b076018455208cb2; Wed, 4 Apr 2018 10:53:02 +0200 From: "Rafael J. Wysocki" To: Linux PM Cc: Peter Zijlstra , Frederic Weisbecker , Thomas Gleixner , Paul McKenney , Thomas Ilsche , Doug Smythies , Rik van Riel , Aubrey Li , Mike Galbraith , LKML , Len Brown Subject: [PATCH v9 07/10] time: hrtimer: Introduce hrtimer_next_event_without() Date: Wed, 04 Apr 2018 10:45:39 +0200 Message-ID: <101528364.6nGUqP0EsC@aspire.rjw.lan> In-Reply-To: <1736751.LdhZHb50jq@aspire.rjw.lan> References: <1736751.LdhZHb50jq@aspire.rjw.lan> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Rafael J. Wysocki The next set of changes will need to compute the time to the next hrtimer event over all hrtimers except for the scheduler tick one. To that end introduce a new helper function, hrtimer_next_event_without(), for computing the time until the next hrtimer event over all timers except for one and modify the underlying code in __hrtimer_next_event_base() to prepare it for being called by that new function. No intentional changes in functionality. Signed-off-by: Rafael J. Wysocki Reviewed-by: Frederic Weisbecker --- v8 -> v9: * Make fewer changes to the existing code. * Add a new helper function for the handling of the use case at hand. --- include/linux/hrtimer.h | 1 kernel/time/hrtimer.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 54 insertions(+), 2 deletions(-) Index: linux-pm/include/linux/hrtimer.h =================================================================== --- linux-pm.orig/include/linux/hrtimer.h +++ linux-pm/include/linux/hrtimer.h @@ -426,6 +426,7 @@ static inline ktime_t hrtimer_get_remain } extern u64 hrtimer_get_next_event(void); +extern u64 hrtimer_next_event_without(const struct hrtimer *exclude); extern bool hrtimer_active(const struct hrtimer *timer); Index: linux-pm/kernel/time/hrtimer.c =================================================================== --- linux-pm.orig/kernel/time/hrtimer.c +++ linux-pm/kernel/time/hrtimer.c @@ -490,6 +490,7 @@ __next_base(struct hrtimer_cpu_base *cpu while ((base = __next_base((cpu_base), &(active)))) static ktime_t __hrtimer_next_event_base(struct hrtimer_cpu_base *cpu_base, + const struct hrtimer *exclude, unsigned int active, ktime_t expires_next) { @@ -502,9 +503,24 @@ static ktime_t __hrtimer_next_event_base next = timerqueue_getnext(&base->active); timer = container_of(next, struct hrtimer, node); + if (timer == exclude) { + /* Get to the next timer in the queue. */ + struct rb_node *rbn = rb_next(&next->node); + + next = rb_entry_safe(rbn, struct timerqueue_node, node); + if (!next) + continue; + + timer = container_of(next, struct hrtimer, node); + } expires = ktime_sub(hrtimer_get_expires(timer), base->offset); if (expires < expires_next) { expires_next = expires; + + /* Skip cpu_base update if a timer is being excluded. */ + if (exclude) + continue; + if (timer->is_soft) cpu_base->softirq_next_timer = timer; else @@ -548,7 +564,8 @@ __hrtimer_get_next_event(struct hrtimer_ if (!cpu_base->softirq_activated && (active_mask & HRTIMER_ACTIVE_SOFT)) { active = cpu_base->active_bases & HRTIMER_ACTIVE_SOFT; cpu_base->softirq_next_timer = NULL; - expires_next = __hrtimer_next_event_base(cpu_base, active, KTIME_MAX); + expires_next = __hrtimer_next_event_base(cpu_base, NULL, + active, KTIME_MAX); next_timer = cpu_base->softirq_next_timer; } @@ -556,7 +573,8 @@ __hrtimer_get_next_event(struct hrtimer_ if (active_mask & HRTIMER_ACTIVE_HARD) { active = cpu_base->active_bases & HRTIMER_ACTIVE_HARD; cpu_base->next_timer = next_timer; - expires_next = __hrtimer_next_event_base(cpu_base, active, expires_next); + expires_next = __hrtimer_next_event_base(cpu_base, NULL, active, + expires_next); } return expires_next; @@ -1200,6 +1218,39 @@ u64 hrtimer_get_next_event(void) raw_spin_unlock_irqrestore(&cpu_base->lock, flags); + return expires; +} + +/** + * hrtimer_next_event_without - time until next expiry event w/o one timer + * @exclude: timer to exclude + * + * Returns the next expiry time over all timers except for the @exclude one or + * KTIME_MAX if none of them is pending. + */ +u64 hrtimer_next_event_without(const struct hrtimer *exclude) +{ + struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); + u64 expires = KTIME_MAX; + unsigned long flags; + + raw_spin_lock_irqsave(&cpu_base->lock, flags); + + if (__hrtimer_hres_active(cpu_base)) { + unsigned int active; + + if (!cpu_base->softirq_activated) { + active = cpu_base->active_bases & HRTIMER_ACTIVE_SOFT; + expires = __hrtimer_next_event_base(cpu_base, exclude, + active, KTIME_MAX); + } + active = cpu_base->active_bases & HRTIMER_ACTIVE_HARD; + expires = __hrtimer_next_event_base(cpu_base, exclude, active, + expires); + } + + raw_spin_unlock_irqrestore(&cpu_base->lock, flags); + return expires; } #endif