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 856E5CE79CE for ; Wed, 20 Sep 2023 14:01:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234929AbjITOB5 (ORCPT ); Wed, 20 Sep 2023 10:01:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234729AbjITOBz (ORCPT ); Wed, 20 Sep 2023 10:01:55 -0400 Received: from out-226.mta0.migadu.com (out-226.mta0.migadu.com [IPv6:2001:41d0:1004:224b::e2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A2A5AC for ; Wed, 20 Sep 2023 07:01:48 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1695218505; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=q5FMu0D+lg+hJ0WRrS1fbyuLn69QOn+cvkKyyXnvWFQ=; b=ZonHdx0zZ+TxdSp20seUHtqn7aIDhF9v3k1JUwdciOcnxZjL66NQrZa1qYfgoSXMsqCQdb zmlHaJGF1jW+vFBNB7B0oXCx3KsaG8HwpMrQgb9HsJ+RGi8di4j/NR2OMMf02tFrHc7eIX UkR22KywqfnEdenLjjNU0kvD8JDplu8= From: Yajun Deng To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com Cc: linux-kernel@vger.kernel.org, Yajun Deng Subject: [PATCH v2] sched/rt: move back to RT_GROUP_SCHED and rename it child Date: Wed, 20 Sep 2023 22:01:27 +0800 Message-Id: <20230920140127.1671945-1-yajun.deng@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The member back in struct sched_rt_entity only related to RT_GROUP_SCHED, it should not place out of RT_GROUP_SCHED, move back to RT_GROUP_SCHED and rename it child. This would save a few bytes. Init child when parent isn't NULL in init_tg_rt_entry() and introduce for_each_sched_rt_entity_reverse() to iterate rt_se from top to down. Signed-off-by: Yajun Deng --- v2: fix the "uninitialized symbol 'root'" warning v1: https://lore.kernel.org/all/20230919035114.2364567-1-yajun.deng@linux.dev/ --- include/linux/sched.h | 2 +- kernel/sched/rt.c | 25 ++++++++++++++++--------- 2 files changed, 17 insertions(+), 10 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 7fcf1b82cfa6..cd05f4bb6a26 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -594,8 +594,8 @@ struct sched_rt_entity { unsigned short on_rq; unsigned short on_list; - struct sched_rt_entity *back; #ifdef CONFIG_RT_GROUP_SCHED + struct sched_rt_entity *child; struct sched_rt_entity *parent; /* rq on which this entity is (to be) queued: */ struct rt_rq *rt_rq; diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 0597ba0f85ff..473a21b76c62 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -230,8 +230,10 @@ void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, if (!parent) rt_se->rt_rq = &rq->rt; - else + else { rt_se->rt_rq = parent->my_q; + parent->child = rt_se; + } rt_se->my_q = rt_rq; rt_se->parent = parent; @@ -564,6 +566,9 @@ static inline struct task_group *next_task_group(struct task_group *tg) #define for_each_sched_rt_entity(rt_se) \ for (; rt_se; rt_se = rt_se->parent) +#define for_each_sched_rt_entity_reverse(rt_se) \ + for (; rt_se; rt_se = rt_se->child) + static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) { return rt_se->my_q; @@ -669,6 +674,9 @@ typedef struct rt_rq *rt_rq_iter_t; #define for_each_sched_rt_entity(rt_se) \ for (; rt_se; rt_se = NULL) +#define for_each_sched_rt_entity_reverse(rt_se) \ + for_each_sched_rt_entity(rt_se) + static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) { return NULL; @@ -1481,22 +1489,21 @@ static void __dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flag */ static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags) { - struct sched_rt_entity *back = NULL; + struct sched_rt_entity *root = NULL; unsigned int rt_nr_running; - for_each_sched_rt_entity(rt_se) { - rt_se->back = back; - back = rt_se; - } + for_each_sched_rt_entity(rt_se) + root = rt_se; - rt_nr_running = rt_rq_of_se(back)->rt_nr_running; + rt_nr_running = rt_rq_of_se(root)->rt_nr_running; - for (rt_se = back; rt_se; rt_se = rt_se->back) { + rt_se = root; + for_each_sched_rt_entity_reverse(rt_se) { if (on_rt_rq(rt_se)) __dequeue_rt_entity(rt_se, flags); } - dequeue_top_rt_rq(rt_rq_of_se(back), rt_nr_running); + dequeue_top_rt_rq(rt_rq_of_se(root), rt_nr_running); } static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags) -- 2.25.1