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 X-Spam-Level: X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A312C4743D for ; Tue, 8 Jun 2021 18:04:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73EA061376 for ; Tue, 8 Jun 2021 18:04:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234143AbhFHSG2 (ORCPT ); Tue, 8 Jun 2021 14:06:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:46060 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231517AbhFHSGN (ORCPT ); Tue, 8 Jun 2021 14:06:13 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C0C2F613B6; Tue, 8 Jun 2021 18:04:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623175460; bh=00P2kEqlsotV9ICqUo0d1XRT9wFCzs4amrD2hE2VfYw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TG8f0qoaRkVt/4KPd1ptI+FZYY+CZ3/6y+VhsArsJY2Uml2uG5L6y5k0NSU8MYrNp xpGpzHr6XiC7nIISbzFmiE/6Slid8y+3k71Bl4BQZquFqZdFtypvCsdwhPNu1cCcVv u39BhY5vGNuVnK/KlHGDeo278Vv4zLB5vsMZPgbdrQELJ05CRQUsMhxAm1wfTHGpDK /3Twu7nBBT9PP5SSBYxe5DSAcPEMvbS0TJaWosLJ1gADkRmmQ5rEIQa0xQz7rl31/g fRw5CyRzDMEDkLG7ui+ve5vS1jy/3PA+BooHa36Hmqndmo2Tucw0aWTFLJjlmwke/C i/z13OYLUbIzw== From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon , Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Quentin Perret , Tejun Heo , Johannes Weiner , Ingo Molnar , Juri Lelli , Vincent Guittot , "Rafael J. Wysocki" , Dietmar Eggemann , Daniel Bristot de Oliveira , Valentin Schneider , Mark Rutland , kernel-team@android.com Subject: [PATCH v9 13/20] sched: Introduce dl_task_check_affinity() to check proposed affinity Date: Tue, 8 Jun 2021 19:03:06 +0100 Message-Id: <20210608180313.11502-14-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210608180313.11502-1-will@kernel.org> References: <20210608180313.11502-1-will@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In preparation for restricting the affinity of a task during execve() on arm64, introduce a new dl_task_check_affinity() helper function to give an indication as to whether the restricted mask is admissible for a deadline task. Reviewed-by: Daniel Bristot de Oliveira Signed-off-by: Will Deacon --- include/linux/sched.h | 6 ++++++ kernel/sched/core.c | 46 +++++++++++++++++++++++++++---------------- 2 files changed, 35 insertions(+), 17 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 91a6cfeae242..b9d0df8f7153 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1691,6 +1691,7 @@ extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); extern void release_user_cpus_ptr(struct task_struct *p); +extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); #else @@ -1713,6 +1714,11 @@ static inline void release_user_cpus_ptr(struct task_struct *p) { WARN_ON(p->user_cpus_ptr); } + +static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) +{ + return 0; +} #endif extern int yield_to(struct task_struct *p, bool preempt); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d3d5e8b33961..d2fe6f8b8f6f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6935,6 +6935,32 @@ SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, return retval; } +#ifdef CONFIG_SMP +int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) +{ + int ret = 0; + + /* + * If the task isn't a deadline task or admission control is + * disabled then we don't care about affinity changes. + */ + if (!task_has_dl_policy(p) || !dl_bandwidth_enabled()) + return 0; + + /* + * Since bandwidth control happens on root_domain basis, + * if admission test is enabled, we only admit -deadline + * tasks allowed to run on all the CPUs in the task's + * root_domain. + */ + rcu_read_lock(); + if (!cpumask_subset(task_rq(p)->rd->span, mask)) + ret = -EBUSY; + rcu_read_unlock(); + return ret; +} +#endif + static int __sched_setaffinity(struct task_struct *p, const struct cpumask *mask) { @@ -6952,23 +6978,9 @@ __sched_setaffinity(struct task_struct *p, const struct cpumask *mask) cpuset_cpus_allowed(p, cpus_allowed); cpumask_and(new_mask, mask, cpus_allowed); - /* - * Since bandwidth control happens on root_domain basis, - * if admission test is enabled, we only admit -deadline - * tasks allowed to run on all the CPUs in the task's - * root_domain. - */ -#ifdef CONFIG_SMP - if (task_has_dl_policy(p) && dl_bandwidth_enabled()) { - rcu_read_lock(); - if (!cpumask_subset(task_rq(p)->rd->span, new_mask)) { - retval = -EBUSY; - rcu_read_unlock(); - goto out_free_new_mask; - } - rcu_read_unlock(); - } -#endif + retval = dl_task_check_affinity(p, new_mask); + if (retval) + goto out_free_new_mask; again: retval = __set_cpus_allowed_ptr(p, new_mask, SCA_CHECK | SCA_USER); if (retval) -- 2.32.0.rc1.229.g3e70b5a671-goog