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 42959C4332F for ; Thu, 20 Oct 2022 01:11:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229990AbiJTBLM (ORCPT ); Wed, 19 Oct 2022 21:11:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229905AbiJTBLE (ORCPT ); Wed, 19 Oct 2022 21:11:04 -0400 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 534801645F9 for ; Wed, 19 Oct 2022 18:11:03 -0700 (PDT) Received: by mail-pf1-x42a.google.com with SMTP id 204so18834965pfx.10 for ; Wed, 19 Oct 2022 18:11:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=4NSOyseBFnL3nwsXsl+tqfsopwFipdmUNqJP3ooKECg=; b=E9Oa32keD+q4jeVumDMAg41KTc4XBw8kCovcEgAwRbI6e2hr/jPOoUNhMAsOBk0ioI 09YwP40DDIeO/2fFJ9e3ENAdOuYPo3Z3ehexjpoNyhntwp8bnjeZQ8rGAYA4Wzc3+ceR 60FBoamG5nr24SMb/49lFPTSy+riRMpt+A3uA7AiURI3pgGv/6yvL4YUU9K8/fGndHby T+1FIiviiFWZVNNE61IjHStUuoh20XoSmZFnX1IITkpV3Eo14RNdMY/FGUrqVMKlSWXq BaYrE5XkB+PY0yewZeZmm51CpzIfcMERDTqc52+dhBTk1BAJsaSJBa0GzanRacGbxeYl fdAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=4NSOyseBFnL3nwsXsl+tqfsopwFipdmUNqJP3ooKECg=; b=vQZDuPJHojAw8omEz3vdacbuG4xH0LhHrWfiC3f/SvS4GDmKSWM/phhWRdasUe4w02 J7Wpq1qvt5CEmorJJp7oZpqikg1tiOaGm5frqknR/9RMr8OHbtZnWhDtqDvsIQseJoaw b35pl3adG72DS6sImw5LZsrvao86S+gYp0Q00iF7rfDYEkwyn4PPr2Yem/bzbZiTZvBo ez0n5v1qcVEwmF+Mt4XRXHlvfESbSmUR7SqzxGSi1n6pfGL7GWEKL57vB9y9RjpG4cVC cp1qeda6mWs3IJE6SFGqnnEvpPrZ6UFYw08M/mU2oWriWYHo8+c+Y3hUTNVY+EnrXaR1 plWg== X-Gm-Message-State: ACrzQf1Oz9oTY7IegztHyI8YQZkDX6WZLd8n7H/TzEfZEyA6vlFycm21 HNvxvwJjvom2TmXetid3hST/FOy3Q682gw== X-Google-Smtp-Source: AMsMyM7LGbdYHU3LBBsneZkJEr/+juWcmiIvZCQiTr4j4HeKksJAm4bnpd1eQtF19wUWwLNpBDz/9g== X-Received: by 2002:a63:4904:0:b0:439:e6a4:a3b5 with SMTP id w4-20020a634904000000b00439e6a4a3b5mr9269287pga.182.1666228262156; Wed, 19 Oct 2022 18:11:02 -0700 (PDT) Received: from laptop.hsd1.wa.comcast.net ([2601:600:8500:5f14:d627:c51e:516e:a105]) by smtp.gmail.com with ESMTPSA id b14-20020a170902650e00b00174fa8cbf31sm11242938plk.303.2022.10.19.18.11.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Oct 2022 18:11:01 -0700 (PDT) From: Andrei Vagin To: linux-kernel@vger.kernel.org Cc: Andrei Vagin , Andy Lutomirski , Christian Brauner , Dietmar Eggemann , Kees Cook , Ingo Molnar , Juri Lelli , Peter Oskolkov , Peter Zijlstra , Tycho Andersen , Will Drewry , Vincent Guittot Subject: [PATCH 2/5] sched: add WF_CURRENT_CPU and externise ttwu Date: Wed, 19 Oct 2022 18:10:45 -0700 Message-Id: <20221020011048.156415-3-avagin@gmail.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20221020011048.156415-1-avagin@gmail.com> References: <20221020011048.156415-1-avagin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 5800b0623ff3..cffa8f314c9a 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 1644242ecd11..ee24141c4942 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2071,12 +2071,13 @@ 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); @@ -3161,6 +3162,8 @@ 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); -- 2.37.2