From nobody Sun Dec 28 17:35:59 2025 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 3A154C10F07 for ; Wed, 6 Dec 2023 06:35:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376810AbjLFGe2 (ORCPT ); Wed, 6 Dec 2023 01:34:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231374AbjLFGe0 (ORCPT ); Wed, 6 Dec 2023 01:34:26 -0500 Received: from out-172.mta0.migadu.com (out-172.mta0.migadu.com [91.218.175.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D040D1BD for ; Tue, 5 Dec 2023 22:34:31 -0800 (PST) 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=1701844469; 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: in-reply-to:in-reply-to:references:references; bh=3+ur4a0hWU+7jS1cQdkoVwB5xk0PqQxzIYs0iU9W36Q=; b=THWr/WsIUQYJV3nh7/K0bWCOiqU/xSaMB1QTvbGUaM8Xrm6iojxUSSW0cF8hUwqCTicbn2 HYKEqJPLH3cDWODr4m7Ph7tt/gohXtZiPp/Hed0RSj8srIVAuDqmJ62G7hrtNgBeHj8T6+ 512YdlsETVcVx7Y8YX4J3WPDz+7UGmQ= 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 1/2] sched/fair: Return NULL when entity isn't a task in task_of() Date: Wed, 6 Dec 2023 14:33:59 +0800 Message-Id: <20231206063400.3206346-2-yajun.deng@linux.dev> In-Reply-To: <20231206063400.3206346-1-yajun.deng@linux.dev> References: <20231206063400.3206346-1-yajun.deng@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Before calling task_of(), we need to make sure that the entity is a task. There is also a warning in task_of() if the entity isn't a task. That means we need to check the entity twice. If the entity isn't a task, return the task struct is meaningless. Return NULL when entity isn't a task in task_of(), and call task_of() instead of entity_is_task() when we need a task_struct. Signed-off-by: Yajun Deng --- kernel/sched/fair.c | 50 +++++++++++++++++++++----------------------- kernel/sched/sched.h | 4 +++- 2 files changed, 27 insertions(+), 27 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index bcd0f230e21f..5003c8501398 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -470,8 +470,10 @@ static int cfs_rq_is_idle(struct cfs_rq *cfs_rq) =20 static int se_is_idle(struct sched_entity *se) { - if (entity_is_task(se)) - return task_has_idle_policy(task_of(se)); + struct task_struct *p =3D task_of(se); + + if (p) + return task_has_idle_policy(p); return cfs_rq_is_idle(group_cfs_rq(se)); } =20 @@ -1156,6 +1158,7 @@ s64 update_curr_common(struct rq *rq) static void update_curr(struct cfs_rq *cfs_rq) { struct sched_entity *curr =3D cfs_rq->curr; + struct task_struct *p; s64 delta_exec; =20 if (unlikely(!curr)) @@ -1169,8 +1172,9 @@ static void update_curr(struct cfs_rq *cfs_rq) update_deadline(cfs_rq, curr); update_min_vruntime(cfs_rq); =20 - if (entity_is_task(curr)) - update_curr_task(task_of(curr), delta_exec); + p =3D task_of(curr); + if (p) + update_curr_task(p, delta_exec); =20 account_cfs_rq_runtime(cfs_rq, delta_exec); } @@ -1184,24 +1188,19 @@ static inline void update_stats_wait_start_fair(struct cfs_rq *cfs_rq, struct sched_entity *s= e) { struct sched_statistics *stats; - struct task_struct *p =3D NULL; =20 if (!schedstat_enabled()) return; =20 stats =3D __schedstats_from_se(se); =20 - if (entity_is_task(se)) - p =3D task_of(se); - - __update_stats_wait_start(rq_of(cfs_rq), p, stats); + __update_stats_wait_start(rq_of(cfs_rq), task_of(se), stats); } =20 static inline void update_stats_wait_end_fair(struct cfs_rq *cfs_rq, struct sched_entity *se) { struct sched_statistics *stats; - struct task_struct *p =3D NULL; =20 if (!schedstat_enabled()) return; @@ -1217,27 +1216,20 @@ update_stats_wait_end_fair(struct cfs_rq *cfs_rq, s= truct sched_entity *se) if (unlikely(!schedstat_val(stats->wait_start))) return; =20 - if (entity_is_task(se)) - p =3D task_of(se); - - __update_stats_wait_end(rq_of(cfs_rq), p, stats); + __update_stats_wait_end(rq_of(cfs_rq), task_of(se), stats); } =20 static inline void update_stats_enqueue_sleeper_fair(struct cfs_rq *cfs_rq, struct sched_enti= ty *se) { struct sched_statistics *stats; - struct task_struct *tsk =3D NULL; =20 if (!schedstat_enabled()) return; =20 stats =3D __schedstats_from_se(se); =20 - if (entity_is_task(se)) - tsk =3D task_of(se); - - __update_stats_enqueue_sleeper(rq_of(cfs_rq), tsk, stats); + __update_stats_enqueue_sleeper(rq_of(cfs_rq), task_of(se), stats); } =20 /* @@ -1263,6 +1255,7 @@ update_stats_enqueue_fair(struct cfs_rq *cfs_rq, stru= ct sched_entity *se, int fl static inline void update_stats_dequeue_fair(struct cfs_rq *cfs_rq, struct sched_entity *se, = int flags) { + struct task_struct *tsk; =20 if (!schedstat_enabled()) return; @@ -1274,8 +1267,8 @@ update_stats_dequeue_fair(struct cfs_rq *cfs_rq, stru= ct sched_entity *se, int fl if (se !=3D cfs_rq->curr) update_stats_wait_end_fair(cfs_rq, se); =20 - if ((flags & DEQUEUE_SLEEP) && entity_is_task(se)) { - struct task_struct *tsk =3D task_of(se); + tsk =3D task_of(se); + if ((flags & DEQUEUE_SLEEP) && tsk) { unsigned int state; =20 /* XXX racy against TTWU */ @@ -3569,12 +3562,14 @@ static inline void update_scan_period(struct task_s= truct *p, int new_cpu) static void account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se) { + struct task_struct *p =3D task_of(se); + update_load_add(&cfs_rq->load, se->load.weight); #ifdef CONFIG_SMP - if (entity_is_task(se)) { + if (p) { struct rq *rq =3D rq_of(cfs_rq); =20 - account_numa_enqueue(rq, task_of(se)); + account_numa_enqueue(rq, p); list_add(&se->group_node, &rq->cfs_tasks); } #endif @@ -3586,10 +3581,12 @@ account_entity_enqueue(struct cfs_rq *cfs_rq, struc= t sched_entity *se) static void account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) { + struct task_struct *p =3D task_of(se); + update_load_sub(&cfs_rq->load, se->load.weight); #ifdef CONFIG_SMP - if (entity_is_task(se)) { - account_numa_dequeue(rq_of(cfs_rq), task_of(se)); + if (p) { + account_numa_dequeue(rq_of(cfs_rq), p); list_del_init(&se->group_node); } #endif @@ -5323,9 +5320,10 @@ static __always_inline void return_cfs_rq_runtime(st= ruct cfs_rq *cfs_rq); static void dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) { + struct task_struct *p =3D task_of(se); int action =3D UPDATE_TG; =20 - if (entity_is_task(se) && task_on_rq_migrating(task_of(se))) + if (p && task_on_rq_migrating(p)) action |=3D DO_DETACH; =20 /* diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 001fe047bd5d..6baba9ebcde1 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1432,7 +1432,9 @@ static inline void update_idle_core(struct rq *rq) { } #ifdef CONFIG_FAIR_GROUP_SCHED static inline struct task_struct *task_of(struct sched_entity *se) { - SCHED_WARN_ON(!entity_is_task(se)); + if (!entity_is_task(se)) + return NULL; + return container_of(se, struct task_struct, se); } =20 --=20 2.25.1 From nobody Sun Dec 28 17:35:59 2025 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 E262EC46CA3 for ; Wed, 6 Dec 2023 06:35:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376732AbjLFGeg (ORCPT ); Wed, 6 Dec 2023 01:34:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376801AbjLFGee (ORCPT ); Wed, 6 Dec 2023 01:34:34 -0500 Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC868D4F for ; Tue, 5 Dec 2023 22:34:39 -0800 (PST) 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=1701844478; 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: in-reply-to:in-reply-to:references:references; bh=0lDBFEoz+SUMLKMlohSt70DLpSaHMM5qAM0YknDYPRc=; b=Jki4iV4V+jHYrHoOxnxxlqEsZzBkU+FuKWila9Z99n4hUwLNHQz0EzSQUNjYBhRnHw23yW CUMJhz/RW0ZCwzxGFYA7Yk1DyIAXDz1Ed0NWI5KHEaWVs4uDdRijRVZyDyzgaagPe9iJKp o0VTbdgdDU9d5P5u4enkXVbOxZI+2CQ= 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 2/2] sched/rt: Return NULL when rt entity isn't a task in rt_task_of() Date: Wed, 6 Dec 2023 14:34:00 +0800 Message-Id: <20231206063400.3206346-3-yajun.deng@linux.dev> In-Reply-To: <20231206063400.3206346-1-yajun.deng@linux.dev> References: <20231206063400.3206346-1-yajun.deng@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Before calling rt_task_of(), we need to make sure that the rt entity is a task. There is also a warning in rt_task_of() if the rt entity isn't a task. That means we need to check the rt entity twice. If the rt entity isn't a task, return the task struct is meaningless. Return NULL when rt entity isn't a task in rt_task_of(), and call rt_task_of() instead of rt_entity_is_task() when we need a task_struct. Signed-off-by: Yajun Deng --- v2: fix 'struct rt_rq' no member named 'highest_prio'. v1: https://lore.kernel.org/all/20231201022704.3526377-1-yajun.deng@linux.d= ev/ --- kernel/sched/rt.c | 60 ++++++++++++++--------------------------------- 1 file changed, 17 insertions(+), 43 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 40d24f64b444..061f5f005c35 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -169,9 +169,9 @@ static void destroy_rt_bandwidth(struct rt_bandwidth *r= t_b) =20 static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) { -#ifdef CONFIG_SCHED_DEBUG - WARN_ON_ONCE(!rt_entity_is_task(rt_se)); -#endif + if (!rt_entity_is_task(rt_se)) + return NULL; + return container_of(rt_se, struct task_struct, rt); } =20 @@ -1266,54 +1266,34 @@ static void __delist_rt_entity(struct sched_rt_enti= ty *rt_se, struct rt_prio_arr rt_se->on_list =3D 0; } =20 -static inline struct sched_statistics * -__schedstats_from_rt_se(struct sched_rt_entity *rt_se) -{ -#ifdef CONFIG_RT_GROUP_SCHED - /* schedstats is not supported for rt group. */ - if (!rt_entity_is_task(rt_se)) - return NULL; -#endif - - return &rt_task_of(rt_se)->stats; -} - static inline void update_stats_wait_start_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt= _se) { - struct sched_statistics *stats; - struct task_struct *p =3D NULL; + struct task_struct *p; =20 if (!schedstat_enabled()) return; =20 - if (rt_entity_is_task(rt_se)) - p =3D rt_task_of(rt_se); - - stats =3D __schedstats_from_rt_se(rt_se); - if (!stats) + p =3D rt_task_of(rt_se); + if (!p) return; =20 - __update_stats_wait_start(rq_of_rt_rq(rt_rq), p, stats); + __update_stats_wait_start(rq_of_rt_rq(rt_rq), p, &p->stats); } =20 static inline void update_stats_enqueue_sleeper_rt(struct rt_rq *rt_rq, struct sched_rt_entit= y *rt_se) { - struct sched_statistics *stats; - struct task_struct *p =3D NULL; + struct task_struct *p; =20 if (!schedstat_enabled()) return; =20 - if (rt_entity_is_task(rt_se)) - p =3D rt_task_of(rt_se); - - stats =3D __schedstats_from_rt_se(rt_se); - if (!stats) + p =3D rt_task_of(rt_se); + if (!p) return; =20 - __update_stats_enqueue_sleeper(rq_of_rt_rq(rt_rq), p, stats); + __update_stats_enqueue_sleeper(rq_of_rt_rq(rt_rq), p, &p->stats); } =20 static inline void @@ -1330,34 +1310,28 @@ update_stats_enqueue_rt(struct rt_rq *rt_rq, struct= sched_rt_entity *rt_se, static inline void update_stats_wait_end_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_s= e) { - struct sched_statistics *stats; - struct task_struct *p =3D NULL; + struct task_struct *p; =20 if (!schedstat_enabled()) return; =20 - if (rt_entity_is_task(rt_se)) - p =3D rt_task_of(rt_se); - - stats =3D __schedstats_from_rt_se(rt_se); - if (!stats) + p =3D rt_task_of(rt_se); + if (!p) return; =20 - __update_stats_wait_end(rq_of_rt_rq(rt_rq), p, stats); + __update_stats_wait_end(rq_of_rt_rq(rt_rq), p, &p->stats); } =20 static inline void update_stats_dequeue_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int flags) { - struct task_struct *p =3D NULL; + struct task_struct *p; =20 if (!schedstat_enabled()) return; =20 - if (rt_entity_is_task(rt_se)) - p =3D rt_task_of(rt_se); - + p =3D rt_task_of(rt_se); if ((flags & DEQUEUE_SLEEP) && p) { unsigned int state; =20 --=20 2.25.1