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 004F8C433EF for ; Wed, 13 Jul 2022 04:06:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233360AbiGMEF7 (ORCPT ); Wed, 13 Jul 2022 00:05:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233613AbiGMEF2 (ORCPT ); Wed, 13 Jul 2022 00:05:28 -0400 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C669DA0E4 for ; Tue, 12 Jul 2022 21:05:26 -0700 (PDT) Received: by mail-pj1-x1030.google.com with SMTP id b8so8883923pjo.5 for ; Tue, 12 Jul 2022 21:05:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=YxO3douG9yaDP325H3l2tI70xR2hZpS+aWxFMUKMRFw=; b=auPbO2h7LsRh0gM5laDsxqiugnJF/UTbb95NxHR5R+lPBv3nn0ZvzDqgNMeEKd5jDt fwZB+f/j3ByGbbss/INMM5XXu5JrDdjPGYXBiybN/XmGIB4Mr3eCfamx3AZ7Mwv39Joc FzHgyfnxjc57xsr8Q/jfz+CiiLIbopxmCz07ZxmjOfyNUIk1TzIdJxUhFRkvryoqqXvb EZGLs8jb0BmSTQ1OQpLI5B0MXL1S4RqHDEvgUj2CCBlyzBJMOB/Z84BS095VX/TdrpnG 8xkHujETtEbEjEscZB/AtQ0bIUPhXUJpyImGqYObrseIuFwJlvOfA8JY8/DVgIhEfI+E S3Sw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=YxO3douG9yaDP325H3l2tI70xR2hZpS+aWxFMUKMRFw=; b=Tf6axrlmHdfMfTLSQecYccZI1WPW+29BywKuNRBkiBuzsVq5uVPOyAUzzlJtKg5BwO MTMQAGvJ47OuK1QsHTUCHmvgkSdFISIKaoTYkxD5giLUmmi9hQyq6PBuYqJSgN+0J/Sz 2ZU0d0P6ZlWH0CLugxuW40XmEXDwPCAdXggCdaWLfvWdV36PNT0XdOLGei0BO3tVcP+0 RRh85EsdeCSzODwt1+f/n29vbiZYaP5HKDmj4IQ7f8ddxVOlmggYkBYKBZQVCDY7XI7S eMJB/O+VpoiHTomhrnyiTgHwca9vcqUtVa/IwYfS60v24PyIqKCqe/z3B5W8Flm/sB+m Zbwg== X-Gm-Message-State: AJIora9T6tqMAbrUNrvXEBl2uz/gpT7hTIp9Hv9NRRQN4+Yt+gcmLCQ8 8QVdoDD1t6d6Wa7BeNhKoGGZKHLLpLo3hUnT X-Google-Smtp-Source: AGRyM1ubREtBdERwinjkfVXTmWC38yQCiY3CzrFHJGyov5zSsVcwROeUDgetNw7hdK0J6h6IqKJY4A== X-Received: by 2002:a17:903:40cc:b0:16c:115d:5e80 with SMTP id t12-20020a17090340cc00b0016c115d5e80mr1282948pld.0.1657685125521; Tue, 12 Jul 2022 21:05:25 -0700 (PDT) Received: from localhost.localdomain ([139.177.225.235]) by smtp.gmail.com with ESMTPSA id y12-20020a17090322cc00b0016bd16f8acbsm6858942plg.114.2022.07.12.21.05.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Jul 2022 21:05:25 -0700 (PDT) From: Chengming Zhou To: mingo@redhat.com, peterz@infradead.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, vschneid@redhat.com Cc: linux-kernel@vger.kernel.org, Chengming Zhou Subject: [PATCH v2 10/10] sched/fair: delete superfluous set_task_rq_fair() Date: Wed, 13 Jul 2022 12:04:30 +0800 Message-Id: <20220713040430.25778-11-zhouchengming@bytedance.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220713040430.25778-1-zhouchengming@bytedance.com> References: <20220713040430.25778-1-zhouchengming@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org set_task_rq() is used when move task across CPUs/groups to change its cfs_rq and parent entity, and it will call set_task_rq_fair() to sync blocked task load_avg just before change its cfs_rq. 1. task migrate CPU: will detach/remove from prev cfs_rq and reset its sched_avg last_update_time to 0, so don't need to sync again. 2. task migrate cgroup: will detach from prev cfs_rq and reset its sched_avg last_update_time to 0, so don't need to sync too. 3. !fair task migrate CPU/cgroup: we stop load tracking for !fair task, reset sched_avg last_update_time to 0 when switched_from_fair(), so don't need it too. So set_task_rq_fair() is not needed anymore, this patch delete it. And delete unused ATTACH_AGE_LOAD feature together. Signed-off-by: Chengming Zhou --- kernel/sched/fair.c | 31 ------------------------------- kernel/sched/features.h | 1 - kernel/sched/sched.h | 8 -------- 3 files changed, 40 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 576028f5a09e..b435eda88468 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3430,37 +3430,6 @@ static inline void update_tg_load_avg(struct cfs_rq *cfs_rq) } } -/* - * Called within set_task_rq() right before setting a task's CPU. The - * caller only guarantees p->pi_lock is held; no other assumptions, - * including the state of rq->lock, should be made. - */ -void set_task_rq_fair(struct sched_entity *se, - struct cfs_rq *prev, struct cfs_rq *next) -{ - u64 p_last_update_time; - u64 n_last_update_time; - - if (!sched_feat(ATTACH_AGE_LOAD)) - return; - - /* - * We are supposed to update the task to "current" time, then its up to - * date and ready to go to new CPU/cfs_rq. But we have difficulty in - * getting what current time is, so simply throw away the out-of-date - * time. This will result in the wakee task is less decayed, but giving - * the wakee more load sounds not bad. - */ - if (!(se->avg.last_update_time && prev)) - return; - - p_last_update_time = cfs_rq_last_update_time(prev); - n_last_update_time = cfs_rq_last_update_time(next); - - __update_load_avg_blocked_se(p_last_update_time, se); - se->avg.last_update_time = n_last_update_time; -} - /* * When on migration a sched_entity joins/leaves the PELT hierarchy, we need to * propagate its contribution. The key to this propagation is the invariant diff --git a/kernel/sched/features.h b/kernel/sched/features.h index ee7f23c76bd3..fb92431d496f 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -85,7 +85,6 @@ SCHED_FEAT(RT_PUSH_IPI, true) SCHED_FEAT(RT_RUNTIME_SHARE, false) SCHED_FEAT(LB_MIN, false) -SCHED_FEAT(ATTACH_AGE_LOAD, true) SCHED_FEAT(WA_IDLE, true) SCHED_FEAT(WA_WEIGHT, true) diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 19e0076e4245..a8ec7af4bd51 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -505,13 +505,6 @@ extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); extern int sched_group_set_idle(struct task_group *tg, long idle); -#ifdef CONFIG_SMP -extern void set_task_rq_fair(struct sched_entity *se, - struct cfs_rq *prev, struct cfs_rq *next); -#else /* !CONFIG_SMP */ -static inline void set_task_rq_fair(struct sched_entity *se, - struct cfs_rq *prev, struct cfs_rq *next) { } -#endif /* CONFIG_SMP */ #endif /* CONFIG_FAIR_GROUP_SCHED */ #else /* CONFIG_CGROUP_SCHED */ @@ -1937,7 +1930,6 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) #endif #ifdef CONFIG_FAIR_GROUP_SCHED - set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]); p->se.cfs_rq = tg->cfs_rq[cpu]; p->se.parent = tg->se[cpu]; p->se.depth = tg->se[cpu] ? tg->se[cpu]->depth + 1 : 0; -- 2.36.1