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 667B4C4332F for ; Fri, 11 Nov 2022 07:32:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233024AbiKKHcO (ORCPT ); Fri, 11 Nov 2022 02:32:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232854AbiKKHcJ (ORCPT ); Fri, 11 Nov 2022 02:32:09 -0500 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 516405B599 for ; Thu, 10 Nov 2022 23:32:08 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id t3-20020a170902e84300b00186ab03043dso3074765plg.20 for ; Thu, 10 Nov 2022 23:32:08 -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=qJqakF/cb4xngAKJ2V4R5RqLyy98cuBZSEz0fOEyQyE=; b=G2Otzz01US+DOi6goCyzMK7tP68iJqbqsKD5nc/uQuFqxTtqVKJqSgQnm9mEnXTj7A XoWso2YI94PIpLITBT9FSPb7Q74RMOrusytAAdR+aO8LX1GmZ6mYwDZiqsRhQ7Gi22Gy B4TSTt6s+/btq3k9nCUUCDSK/tsrMIqRMaK/xGs4a7Tc57IIACF/EEif4lFW0zWJwyvv jISfhJ6dcJswhGTKkku3MgbV2KwiAoLenii5IzwONSooP51bmg3OQoTDSrO2Glx58DpZ kVtLTDlCbeb7/XZyHXeyM0sYovlLwbCtpZm+dhiwVJILaPSnxtJSVqx1bKhGibKw1cl3 KONw== 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=qJqakF/cb4xngAKJ2V4R5RqLyy98cuBZSEz0fOEyQyE=; b=uzEMSmk4fsUmerW3K3s/cWpPJC/2al3MdfAEc9NM7NOMAZGpoqYxMp0PhrMS/rJ1Z3 9FE9o+prgP61OlYjVEF3nB9fiWxrvJPTU4iS2dO7K+POwPZ3fsQ0xJwWF+83amR7+Grh T6xQfnbs69xrrEzDk6cPkQq78ytiXptHUZyezHMqZ1WNvg1GWPb9f1WQpd3pgbRI5crL RNoQcpg4ddh0dER6AYPCe4azQE5wqV1Wys/koA0EVTg53wu+ZTlgi0j10CwnH1WY8Sl1 TjoC+VG744BuvVH0+QLBZo1XnP/J0NfPQMfb7WbAyPsoG8cQJ1CknLQDs+t8WLTfIKRD 7FVQ== X-Gm-Message-State: ANoB5plnBlA8MJNRExlr971iZ+KSIAduNBGNv1NRIFG0vS2paOfOtA1a LKN7jNXRWCeaoC1sLA96MfKdVkrVYXE= X-Google-Smtp-Source: AA0mqf56NlSTNAmS1SSIjJydNdN8gscB0Ne+rGIBCmPLknLmZzp8IJYFcFvjgBP9VWg3RlNDi3GFqrG8qP0= X-Received: from avagin.kir.corp.google.com ([2620:0:1008:11:8cf3:f53:2863:82a3]) (user=avagin job=sendgmr) by 2002:a17:902:9349:b0:17e:802b:fd6e with SMTP id g9-20020a170902934900b0017e802bfd6emr1101537plp.116.1668151927844; Thu, 10 Nov 2022 23:32:07 -0800 (PST) Date: Thu, 10 Nov 2022 23:31:51 -0800 In-Reply-To: <20221111073154.784261-1-avagin@google.com> Mime-Version: 1.0 References: <20221111073154.784261-1-avagin@google.com> X-Mailer: git-send-email 2.38.1.493.g58b659f92b-goog Message-ID: <20221111073154.784261-3-avagin@google.com> Subject: [PATCH 2/5] sched: add WF_CURRENT_CPU and externise ttwu From: Andrei Vagin To: Kees Cook , Peter Zijlstra , Christian Brauner Cc: linux-kernel@vger.kernel.org, Andrei Vagin , Andy Lutomirski , Dietmar Eggemann , Ingo Molnar , Juri Lelli , Peter Oskolkov , Tycho Andersen , Will Drewry , Vincent Guittot 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 such as UMCG. 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 cb2aa2b54c7a..4b591e7773fd 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4039,8 +4039,7 @@ 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 e4a0b8bd941c..4ebe7222664c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7204,6 +7204,10 @@ 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 a4a20046e586..4c275f41773c 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2077,12 +2077,13 @@ 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); @@ -3167,6 +3168,8 @@ 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); -- 2.38.1.493.g58b659f92b-goog