From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C763B3E2ABA for ; Fri, 28 Aug 2026 07:56:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787903816; cv=none; b=r+ucCfMCf4njv9ed6/HccQFN3iJhNRn4ihuuFAeftYiM3GctkHH+kZc8HUy/V0Yno71EQhKFhEAnRqc/bUzq//Ahiyx720qBF5563rf+JlsnSjpjgF41y7bYpTpUUHdBvZCmZX6OiZZ0ZivxdzOyHq2zNHJAN+vM2nMu7a9NpYo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787903816; c=relaxed/simple; bh=SaMMzbjl6vWNTPXE3AZLpzSOl7NrxKo9JJPuMhsHP6A=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=NdR+1cVoKuniChn7BAEeDv2lHCku6AXQ2tcXHLXNGRoWsLbT1CTMR03O3ELAUw546d3oIGUB0LMEHfaRdCOjaSYKboMTAyarrLUB6DlP1oHn6gJiJZiom9V6jKTm/Nzp6Wv6N8FopPnrFxWs1IQ1WTC2qkz8YaZsE9WiNGw31W0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=pass smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=MDdq5Epw; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="MDdq5Epw" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=LLqdVHIkMiv21YiQRIUu7pIEo2mOwrqXr51hi7vMDCQ=; b=MDdq5EpwwhgNWz2LfuBaaXTuwL lLAt1ecvyKCwSVZkmTz2FNkfbW/gw+/l6epKwsZrZaGT4V/ec74JqvGy4T8hLPdcbogaTivqKSR0w Ge7EnhyjcHU7DkjLuw0jyo9nTQm8P3Cfq1icZ97tx8xgBEOPcDFWWwIIDYO6qdDLolCL11L1TCdjB zFDrg7W0fOsUDFPdjynqX5Sh6mMVrhga/6i9ylwDKnwEueGxTAEcCqkYeI56HnlLRSW63LnIT/E5C z9CoexL9f6/55vVvDk94Zq2z6RgDM4sWcytAVrN8WziFLOViREnDL3h7IeYwvNrsmt0ven54C6tPH /pjbeVCA==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.99.2 #2 (Red Hat Linux)) id 1wzrS1-000000086R0-3ECb; Fri, 28 Aug 2026 07:56:37 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id 42DA83008E2; Fri, 28 Aug 2026 09:56:36 +0200 (CEST) Message-ID: <20260828075558.438093356@infradead.org> User-Agent: quilt/0.68 Date: Fri, 28 Aug 2026 09:41:01 +0200 From: Peter Zijlstra To: mingo@kernel.org Cc: peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, kprateek.nayak@amd.com, tj@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/4] sched/fair: Fold cfs_rq_of(se) into for_each_sched_entity() References: <20260828074059.232353141@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Pretty much every for_each_sched_entity() loop does: cfs_rq = cfs_rq_of(se) as the very first thing. Fold it into the for_each_sched_entity() macro. This paves the way to have the macro track a backlink transparantly. Signed-off-by: Peter Zijlstra (Intel) --- kernel/sched/fair.c | 81 +++++++++++++++++++++++----------------------------- 1 file changed, 37 insertions(+), 44 deletions(-) --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -317,8 +317,8 @@ const struct sched_class fair_sched_clas #ifdef CONFIG_FAIR_GROUP_SCHED /* Walk up scheduling entities hierarchy */ -#define for_each_sched_entity(se) \ - for (; se; se = se->parent) +#define for_each_sched_entity(se, cfs_rq) \ + for (; (se) && ((cfs_rq) = cfs_rq_of(se)); (se) = (se)->parent) static inline bool list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq) { @@ -452,8 +452,8 @@ static int se_is_idle(struct sched_entit #else /* !CONFIG_FAIR_GROUP_SCHED: */ -#define for_each_sched_entity(se) \ - for (; se; se = NULL) +#define for_each_sched_entity(se, cfs_rq) \ + for (; (se) && ((cfs_rq) = cfs_of_of(se)); (se) = NULL) static inline bool list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq) { @@ -2075,9 +2075,10 @@ static void update_curr(struct cfs_rq *c static void update_curr_fair(struct rq *rq) { struct sched_entity *se = &rq->donor->se; + struct cfs_rq *cfs_rq; - for_each_sched_entity(se) - update_curr(cfs_rq_of(se)); + for_each_sched_entity(se, cfs_rq) + update_curr(cfs_rq); } static inline void @@ -4800,18 +4801,19 @@ static void reweight_task_fair(struct rq { struct sched_entity *se = &p->se; unsigned long weight = NICE_0_LOAD; + struct cfs_rq *cfs_rq = cfs_rq_of(se); if (se->on_rq) update_curr_fair(rq); - reweight_entity(cfs_rq_of(se), se, lw->weight); + reweight_entity(cfs_rq, se, lw->weight); se->load.inv_weight = lw->inv_weight; if (!se->on_rq) return; - for_each_sched_entity(se) - weight = __calc_prop_weight(cfs_rq_of(se), se, weight); + for_each_sched_entity(se, cfs_rq) + weight = __calc_prop_weight(cfs_rq, se, weight); reweight_eevdf(&rq->cfs, &p->se, weight, p->se.on_rq); } @@ -6382,6 +6384,8 @@ static __always_inline void return_cfs_r static void set_delayed(struct sched_entity *se) { + struct cfs_rq *cfs_rq; + se->sched_delayed = 1; /* @@ -6392,15 +6396,14 @@ static void set_delayed(struct sched_ent if (!entity_is_task(se)) return; - for_each_sched_entity(se) { - struct cfs_rq *cfs_rq = cfs_rq_of(se); - + for_each_sched_entity(se, cfs_rq) cfs_rq->h_nr_runnable--; - } } static void clear_delayed(struct sched_entity *se) { + struct cfs_rq *cfs_rq; + se->sched_delayed = 0; /* @@ -6412,11 +6415,8 @@ static void clear_delayed(struct sched_e if (!entity_is_task(se)) return; - for_each_sched_entity(se) { - struct cfs_rq *cfs_rq = cfs_rq_of(se); - + for_each_sched_entity(se, cfs_rq) cfs_rq->h_nr_runnable++; - } } static void @@ -7078,14 +7078,16 @@ void unthrottle_cfs_rq(struct cfs_rq *cf walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq); if (!cfs_rq->load.weight) { + struct cfs_rq *cfs_rq_se; + if (!cfs_rq->on_list) return; /* * Nothing to run but something to decay (on_list)? * Complete the branch. */ - for_each_sched_entity(se) { - if (list_add_leaf_cfs_rq(cfs_rq_of(se))) + for_each_sched_entity(se, cfs_rq_se) { + if (list_add_leaf_cfs_rq(cfs_rq_se)) break; } } @@ -7931,13 +7933,12 @@ static unsigned long enqueue_hierarchy(s struct sched_entity *se = &p->se; int h_nr_idle = task_has_idle_policy(p); int h_nr_runnable = 1; + struct cfs_rq *cfs_rq; if (task_new && se->sched_delayed) h_nr_runnable = 0; - for_each_sched_entity(se) { - struct cfs_rq *cfs_rq = cfs_rq_of(se); - + for_each_sched_entity(se, cfs_rq) { update_curr(cfs_rq); if (!se->on_rq) { @@ -8066,16 +8067,15 @@ static void dequeue_hierarchy(struct tas bool task_sleep = flags & DEQUEUE_SLEEP; bool task_delayed = flags & DEQUEUE_DELAYED; bool task_throttled = flags & DEQUEUE_THROTTLE; - int h_nr_runnable = 0; int h_nr_idle = task_has_idle_policy(p); + int h_nr_runnable = 0; + struct cfs_rq *cfs_rq; bool dequeue = true; if (task_sleep || task_delayed || !se->sched_delayed) h_nr_runnable = 1; - for_each_sched_entity(se) { - struct cfs_rq *cfs_rq = cfs_rq_of(se); - + for_each_sched_entity(se, cfs_rq) { update_curr(cfs_rq); if (dequeue) { @@ -11301,8 +11301,7 @@ static void update_cfs_rq_h_load(struct return; WRITE_ONCE(cfs_rq->h_load_next, NULL); - for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); + for_each_sched_entity(se, cfs_rq) { WRITE_ONCE(cfs_rq->h_load_next, se); if (cfs_rq->last_h_load_update == now) break; @@ -14948,9 +14947,9 @@ static inline void task_tick_core(struct static void se_fi_update(const struct sched_entity *se, unsigned int fi_seq, bool forceidle) { - for_each_sched_entity(se) { - struct cfs_rq *cfs_rq = cfs_rq_of(se); + struct cfs_rq *cfs_rq; + for_each_sched_entity(se, cfs_rq) { if (forceidle) { if (cfs_rq->forceidle_seq == fi_seq) break; @@ -15028,10 +15027,8 @@ static void task_tick_fair(struct rq *rq unsigned long weight = NICE_0_LOAD; struct cfs_rq *cfs_rq; - for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); + for_each_sched_entity(se, cfs_rq) { entity_tick(cfs_rq, se, hrtick); - weight = __calc_prop_weight(cfs_rq, se, weight); } @@ -15113,9 +15110,7 @@ static void propagate_entity_cfs_rq(stru /* Start to propagate at parent */ se = se->parent; - for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); - + for_each_sched_entity(se, cfs_rq) { update_load_avg(cfs_rq, se, UPDATE_TG); if (!cfs_rq_pelt_clock_throttled(cfs_rq)) @@ -15218,9 +15213,7 @@ static void set_next_task_fair(struct rq if (on_rq) __dequeue_entity(cfs_rq, se); - for_each_sched_entity(se) { - cfs_rq = cfs_rq_of(se); - + for_each_sched_entity(se, cfs_rq) { if (!IS_ENABLED(CONFIG_FAIR_GROUP_SCHED) || !first || !cfs_rq->h_curr) set_next_entity(cfs_rq, se); @@ -15420,13 +15413,14 @@ static int __sched_group_set_shares(stru for_each_possible_cpu(i) { struct rq *rq = cpu_rq(i); struct sched_entity *se = tg_se(tg, i); + struct cfs_rq *cfs_rq; struct rq_flags rf; /* Propagate contribution to hierarchy */ rq_lock_irqsave(rq, &rf); update_rq_clock(rq); - for_each_sched_entity(se) { - update_load_avg(cfs_rq_of(se), se, UPDATE_TG); + for_each_sched_entity(se, cfs_rq) { + update_load_avg(cfs_rq, se, UPDATE_TG); update_cfs_group(se); } rq_unlock_irqrestore(rq, &rf); @@ -15473,6 +15467,7 @@ int sched_group_set_idle(struct task_gro struct sched_entity *se = tg_se(tg, i); struct cfs_rq *grp_cfs_rq = tg_cfs_rq(tg, i); bool was_idle = cfs_rq_is_idle(grp_cfs_rq); + struct cfs_rq *cfs_rq; long idle_task_delta; struct rq_flags rf; @@ -15487,9 +15482,7 @@ int sched_group_set_idle(struct task_gro if (!cfs_rq_is_idle(grp_cfs_rq)) idle_task_delta *= -1; - for_each_sched_entity(se) { - struct cfs_rq *cfs_rq = cfs_rq_of(se); - + for_each_sched_entity(se, cfs_rq) { if (!se->on_rq) break;