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=-9.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,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 8C1E6C47254 for ; Sat, 2 May 2020 18:29:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6F292206CD for ; Sat, 2 May 2020 18:29:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="ng0OxEs4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728545AbgEBS33 (ORCPT ); Sat, 2 May 2020 14:29:29 -0400 Received: from mail26.static.mailgun.info ([104.130.122.26]:30235 "EHLO mail26.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728263AbgEBS32 (ORCPT ); Sat, 2 May 2020 14:29:28 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588444167; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=keDgvDbjoMHFg8plVEvcXBXvKgiI79nlwlmTptOT3Co=; b=ng0OxEs4RtEqyX1yoiRfHObI/9jmj9sXQ9JNNWhiQhEesUnBLj28prYd9lSK9aum3W2e5Kdy bHx2268lxfsK/gZBcNf0r3I4woACmY32HEIUNJ4C/QWeueYuz1hgJdy+6i+yP8ZaNNVzP3dl tJnbzwIkDya4CuvwwZu9+g3x/as= X-Mailgun-Sending-Ip: 104.130.122.26 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5eadbbf8.7f5056766228-smtp-out-n05; Sat, 02 May 2020 18:29:12 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 5A355C432C2; Sat, 2 May 2020 18:29:11 +0000 (UTC) Received: from th-lint-038.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: psodagud) by smtp.codeaurora.org (Postfix) with ESMTPSA id 3D4A0C433BA; Sat, 2 May 2020 18:29:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 3D4A0C433BA Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=psodagud@codeaurora.org From: Prasad Sodagudi To: tglx@linutronix.de, john.stultz@linaro.org, sboyd@kernel.org, tj@kernel.org Cc: linux-kernel@vger.kernel.org, saravanak@google.com, psodagud@codeaurora.org, pkondeti@codeaurora.org Subject: [PATCH v3 2/2] sched: Add a check for cpu unbound deferrable timers Date: Sat, 2 May 2020 11:28:57 -0700 Message-Id: <1588444137-18651-3-git-send-email-psodagud@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1588444137-18651-1-git-send-email-psodagud@codeaurora.org> References: <1588444137-18651-1-git-send-email-psodagud@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a check to find expired unbound deferrable timers and trigger softirq for handling timers. This way a CPU can process all the expired deferrable timers whenever it is out off idle state due to an interrupt. Signed-off-by: Prasad Sodagudi --- include/linux/timer.h | 3 +++ kernel/time/tick-sched.c | 8 +++++++- kernel/time/timer.c | 29 ++++++++++++++++++++++++++++- 3 files changed, 38 insertions(+), 2 deletions(-) diff --git a/include/linux/timer.h b/include/linux/timer.h index 0dc19a8..e85dd2d 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -172,6 +172,9 @@ extern int del_timer(struct timer_list * timer); extern int mod_timer(struct timer_list *timer, unsigned long expires); extern int mod_timer_pending(struct timer_list *timer, unsigned long expires); extern int timer_reduce(struct timer_list *timer, unsigned long expires); +#ifdef CONFIG_SMP +extern bool check_pending_deferrable_timers(int cpu); +#endif /* * The jiffies value which is added to now, when there is no timer diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 3e2dc9b..16aec80 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -1274,8 +1275,13 @@ static inline void tick_nohz_irq_enter(void) now = ktime_get(); if (ts->idle_active) tick_nohz_stop_idle(ts, now); - if (ts->tick_stopped) + if (ts->tick_stopped) { tick_nohz_update_jiffies(now); +#ifdef CONFIG_SMP + if (check_pending_deferrable_timers(smp_processor_id())) + raise_softirq_irqoff(TIMER_SOFTIRQ); +#endif + } } #else diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 1bf9b49..5947c63 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -221,6 +221,7 @@ static DECLARE_WORK(timer_update_work, timer_update_keys); #ifdef CONFIG_SMP struct timer_base timer_base_deferrable; +static atomic_t deferrable_pending; unsigned int sysctl_timer_migration = 1; DEFINE_STATIC_KEY_FALSE(timers_migration_enabled); @@ -1610,6 +1611,31 @@ static u64 cmp_next_hrtimer_event(u64 basem, u64 expires) return DIV_ROUND_UP_ULL(nextevt, TICK_NSEC) * TICK_NSEC; } + +#ifdef CONFIG_SMP +/* + * check_pending_deferrable_timers - Check for unbound deferrable timer expiry + * @cpu - Current CPU + * + * The function checks whether any global deferrable pending timers + * are exipired or not. This function does not check cpu bounded + * diferrable pending timers expiry. + * + * The function returns true when a cpu unbounded deferrable timer is expired. + */ +bool check_pending_deferrable_timers(int cpu) +{ + if (cpu == tick_do_timer_cpu || + tick_do_timer_cpu == TICK_DO_TIMER_NONE) { + if (time_after_eq(jiffies, timer_base_deferrable.clk) + && !atomic_cmpxchg(&deferrable_pending, 0, 1)) { + return true; + } + } + return false; +} +#endif + /** * get_next_timer_interrupt - return the time (clock mono) of the next timer * @basej: base time jiffies @@ -1801,7 +1827,8 @@ static __latent_entropy void run_timer_softirq(struct softirq_action *h) if (IS_ENABLED(CONFIG_NO_HZ_COMMON)) { __run_timers(this_cpu_ptr(&timer_bases[BASE_DEF])); #ifdef CONFIG_SMP - if (tick_do_timer_cpu == TICK_DO_TIMER_NONE || + if ((atomic_cmpxchg(&deferrable_pending, 1, 0) && + tick_do_timer_cpu == TICK_DO_TIMER_NONE) || tick_do_timer_cpu == smp_processor_id()) __run_timers(&timer_base_deferrable); #endif -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project