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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38F6DC54EBC for ; Tue, 10 Jan 2023 21:32:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232715AbjAJVbv (ORCPT ); Tue, 10 Jan 2023 16:31:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234862AbjAJVbC (ORCPT ); Tue, 10 Jan 2023 16:31:02 -0500 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C36C36534B for ; Tue, 10 Jan 2023 13:30:21 -0800 (PST) Received: by mail-pj1-x104a.google.com with SMTP id r5-20020a17090a1bc500b00227067dde1eso3614448pjr.0 for ; Tue, 10 Jan 2023 13:30:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=er80A9Er8wBpxR2BIE0p2D2/xkiobfzzZD4tbBwSUuc=; b=k7kio1FL9Eg0JJeN23HIDqJzpDd/aXo24nWXA8QtE26rzS8NIcltXZhsRIlZMJ/v4y FFL90KgnLTpkw1lLYymV6ADXdp5aTBQFGoW/wwuZWYtoaI0yAtVlEWUoLZyRcnsjdNBi JT3BNX2YSuH9BnOBoE/oeMVzlB/ShvfW9zWuGCfcHHZJGFMQ+IHSYZwpZbmHCUMzb27R ej317WRq8YkKUX6P8M+rM3r5REU7oFpoNuUkoGCut433ssPdvnJ8ILCQi9Ks2QR+GZWj yYdrXk1tL6llthn89LX846SNzgDrI4Z2ToHsY9Vr3IhA/1ymq2oE6tNHQhaHGzgxsXQ2 M2Xg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=er80A9Er8wBpxR2BIE0p2D2/xkiobfzzZD4tbBwSUuc=; b=TTaZS+K84JXkm1xMvI2M+1JC4EBVlVuoXE6L1xjBU0GaSoRiBi1G+xGXO9AvLIQGgZ I8qABCMIf1PkAP0u0QFm0WNqdPmDeEzIzE9ApS9RJ82capkb+7Kf+UUOPmOuJweD6HKD 4rTaOwTMI8qNd+3QOT8WWJrx6g/c+ec2H4gnn73A7dI3g/ocU3AHLkfORNHtBa/lH7ka FwDKwZvjqBFnIUDGeykI46S+ug9jdw5LxdHoFRmM5AmFzsaXMMUAvpN72ziv669CSMYK 7bpquvM6YpfNv6Ug8OUcx3qJhg9PyygK6ddyQlR5cotd84t6Pnvwso7XxjAH3a/7C4Ay br5g== X-Gm-Message-State: AFqh2koKtqts7scJmxzwNMfoXWTYmm7qizf8lDDNWFcSr91JQcoLJi8S HXxTHEDLDBfwlajjXF0U3BeH6IMVh6Y= X-Google-Smtp-Source: AMrXdXtj0wrADAOgf+zF9QujslNiLfEm/Juh4EPsEFD/mE7R9rd6zhbudUg4fgg8yDp8PqaGX8+6nFDBnOY= X-Received: from avagin.kir.corp.google.com ([2620:0:1008:11:6203:13b5:2d85:b75c]) (user=avagin job=sendgmr) by 2002:a62:3683:0:b0:578:47f4:e0ec with SMTP id d125-20020a623683000000b0057847f4e0ecmr5429470pfa.60.1673386221162; Tue, 10 Jan 2023 13:30:21 -0800 (PST) Date: Tue, 10 Jan 2023 13:30:07 -0800 In-Reply-To: <20230110213010.2683185-1-avagin@google.com> Mime-Version: 1.0 References: <20230110213010.2683185-1-avagin@google.com> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog Message-ID: <20230110213010.2683185-3-avagin@google.com> Subject: [PATCH 2/5] sched: add WF_CURRENT_CPU and externise ttwu From: Andrei Vagin To: Peter Zijlstra , Ingo Molnar , Vincent Guittot , Dietmar Eggemann Cc: linux-kernel@vger.kernel.org, Kees Cook , Christian Brauner , Andrei Vagin , Andy Lutomirski , Juri Lelli , Peter Oskolkov , Tycho Andersen , Will Drewry Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Oskolkov Add WF_CURRENT_CPU wake flag that advices the scheduler to move the wakee to the current CPU. This is useful for fast on-CPU context switching use cases. In addition, make ttwu external rather than static so that the flag could be passed to it from outside of sched/core.c. Signed-off-by: Peter Oskolkov Signed-off-by: Andrei Vagin --- kernel/sched/core.c | 3 +-- kernel/sched/fair.c | 4 ++++ kernel/sched/sched.h | 13 ++++++++----- 3 files changed, 13 insertions(+), 7 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 25b582b6ee5f..6478e819eb99 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4063,8 +4063,7 @@ bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) * Return: %true if @p->state changes (an actual wakeup was done), * %false otherwise. */ -static int -try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) +int try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) { unsigned long flags; int cpu, success = 0; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index c36aa54ae071..d6f76bead3c5 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7380,6 +7380,10 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags) if (wake_flags & WF_TTWU) { record_wakee(p); + if ((wake_flags & WF_CURRENT_CPU) && + cpumask_test_cpu(cpu, p->cpus_ptr)) + return cpu; + if (sched_energy_enabled()) { new_cpu = find_energy_efficient_cpu(p, prev_cpu); if (new_cpu >= 0) diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 771f8ddb7053..34b4c54b2a2a 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2088,12 +2088,13 @@ static inline int task_on_rq_migrating(struct task_struct *p) } /* Wake flags. The first three directly map to some SD flag value */ -#define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ -#define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ -#define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ +#define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ +#define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ +#define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ -#define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ -#define WF_MIGRATED 0x20 /* Internal use, task got migrated */ +#define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ +#define WF_MIGRATED 0x20 /* Internal use, task got migrated */ +#define WF_CURRENT_CPU 0x40 /* Prefer to move the wakee to the current CPU. */ #ifdef CONFIG_SMP static_assert(WF_EXEC == SD_BALANCE_EXEC); @@ -3245,6 +3246,8 @@ static inline bool is_per_cpu_kthread(struct task_struct *p) extern void swake_up_all_locked(struct swait_queue_head *q); extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); +extern int try_to_wake_up(struct task_struct *tsk, unsigned int state, int wake_flags); + #ifdef CONFIG_PREEMPT_DYNAMIC extern int preempt_dynamic_mode; extern int sched_dynamic_mode(const char *str); -- 2.39.0.314.g84b9a713c41-goog