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 4957CE7C4D0 for ; Wed, 4 Oct 2023 15:35:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242883AbjJDPfq (ORCPT ); Wed, 4 Oct 2023 11:35:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233692AbjJDPfm (ORCPT ); Wed, 4 Oct 2023 11:35:42 -0400 Received: from out-203.mta1.migadu.com (out-203.mta1.migadu.com [IPv6:2001:41d0:203:375::cb]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF83FCE for ; Wed, 4 Oct 2023 08:35:38 -0700 (PDT) Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1696433736; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4sRnG2yg4I61J1F96z6/qMAsZlsk2UA4qVDxZItMXbI=; b=ajupj+mSkKwsdquRS64v2Myg5+yUBTjoB4o2b0tk8+3jf60EDCB3kwQPr4RrwoPLMGCKrh kkuxKyEXa0rFrleqFP7GvunVjH0SlbWIYA+jYrdmXfGe/u1DS3m9JHqGZdg4yjxVCJyRI5 /ZwGctS4isFv8tDGs5lUojdozRWCUIA= Date: Wed, 4 Oct 2023 23:35:26 +0800 MIME-Version: 1.0 Subject: Re: [PATCH v4] sched/rt: move back to RT_GROUP_SCHED and rename it child Content-Language: en-US To: Peter Zijlstra Cc: Ingo Molnar , mingo@redhat.com, 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, linux-kernel@vger.kernel.org, kernel test robot References: <20230803050317.2240948-1-yajun.deng@linux.dev> <93aa2ee6-3ee4-0129-7160-d3684ba67f56@linux.dev> <20231003163719.GG1539@noisy.programming.kicks-ass.net> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yajun Deng In-Reply-To: <20231003163719.GG1539@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/10/4 00:37, Peter Zijlstra wrote: > On Tue, Oct 03, 2023 at 10:55:50PM +0800, Yajun Deng wrote: > >> @Peter, I think I split up this patch into 2 separate patches: >> >>          sched/rt: Introduce for_each_sched_rt_entity_back() & use it > Why ?? Having that macro makes no sense what so ever. You can't use it, > unless you set up the back pointers first. It is not a self contained > piece of functionality. The 2nd patch rely on this patch. It will be used in dequeue_rt_stack. We need to add a macro first, because the 'back' will be not exist after the 2nd patch when disable CONFIG_RT_GROUP_SCHED. diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 88fc98601413..0b6b4a715d6e 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -520,6 +520,9 @@ 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_back(rt_se) \ +    for (; rt_se; rt_se = rt_se->back) +  static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)  {      return rt_se->my_q; @@ -625,6 +628,9 @@ 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_back(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; @@ -1445,7 +1451,8 @@ static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags)      rt_nr_running = rt_rq_of_se(back)->rt_nr_running; -    for (rt_se = back; rt_se; rt_se = rt_se->back) { +    rt_se = back; +    for_each_sched_rt_entity_back(rt_se) {          if (on_rt_rq(rt_se))              __dequeue_rt_entity(rt_se, flags);      } > >>         sched/rt: Move sched_rt_entity::back to under the >> CONFIG_RT_GROUP_SCHED block > This one sure.