From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 34FA4A94D for ; Mon, 28 Aug 2023 10:46:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A19B9C433C8; Mon, 28 Aug 2023 10:46:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693219609; bh=KByocBs1Ic8UB9p1yiTvXp477zOYX76wArESZB7cJ8Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wyzCdfp5CrdaYlBHxT96fYIYieKbjZYxE84Z1JTgVgreNcrXbEmmtLewHwhoR4lD8 PgcddhCRBbTbnd8ADFe2pGe0pgITEvI+xjQVfhgWryepDiMXT122O85JU9KK4Be7Wz kVfLJh09Q3bMVSfJEWmySRV98NnH83OlpZ+gGvuU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Waiman Long , Dietmar Eggemann , Juri Lelli , Tejun Heo , "Qais Yousef (Google)" Subject: [PATCH 5.15 79/89] cgroup/cpuset: Free DL BW in case can_attach() fails Date: Mon, 28 Aug 2023 12:14:20 +0200 Message-ID: <20230828101152.886061991@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101150.163430842@linuxfoundation.org> References: <20230828101150.163430842@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dietmar Eggemann commit 2ef269ef1ac006acf974793d975539244d77b28f upstream. cpuset_can_attach() can fail. Postpone DL BW allocation until all tasks have been checked. DL BW is not allocated per-task but as a sum over all DL tasks migrating. If multiple controllers are attached to the cgroup next to the cpuset controller a non-cpuset can_attach() can fail. In this case free DL BW in cpuset_cancel_attach(). Finally, update cpuset DL task count (nr_deadline_tasks) only in cpuset_attach(). Suggested-by: Waiman Long Signed-off-by: Dietmar Eggemann Signed-off-by: Juri Lelli Reviewed-by: Waiman Long Signed-off-by: Tejun Heo [ Conflict in kernel/cgroup/cpuset.c due to pulling extra neighboring functions that are not applicable on this branch. ] Signed-off-by: Qais Yousef (Google) Signed-off-by: Greg Kroah-Hartman --- include/linux/sched.h | 2 - kernel/cgroup/cpuset.c | 51 +++++++++++++++++++++++++++++++++++++++++++++---- kernel/sched/core.c | 17 +--------------- 3 files changed, 50 insertions(+), 20 deletions(-) --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1797,7 +1797,7 @@ current_restore_flags(unsigned long orig } extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); -extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_effective_cpus); +extern int task_can_attach(struct task_struct *p); extern int dl_bw_alloc(int cpu, u64 dl_bw); extern void dl_bw_free(int cpu, u64 dl_bw); #ifdef CONFIG_SMP --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -167,6 +167,8 @@ struct cpuset { * know when to rebuild associated root domain bandwidth information. */ int nr_deadline_tasks; + int nr_migrate_dl_tasks; + u64 sum_migrate_dl_bw; /* Handle for cpuset.cpus.partition */ struct cgroup_file partition_file; @@ -2206,16 +2208,23 @@ static int fmeter_getrate(struct fmeter static struct cpuset *cpuset_attach_old_cs; +static void reset_migrate_dl_data(struct cpuset *cs) +{ + cs->nr_migrate_dl_tasks = 0; + cs->sum_migrate_dl_bw = 0; +} + /* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */ static int cpuset_can_attach(struct cgroup_taskset *tset) { struct cgroup_subsys_state *css; - struct cpuset *cs; + struct cpuset *cs, *oldcs; struct task_struct *task; int ret; /* used later by cpuset_attach() */ cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset, &css)); + oldcs = cpuset_attach_old_cs; cs = css_cs(css); mutex_lock(&cpuset_mutex); @@ -2227,7 +2236,7 @@ static int cpuset_can_attach(struct cgro goto out_unlock; cgroup_taskset_for_each(task, css, tset) { - ret = task_can_attach(task, cs->effective_cpus); + ret = task_can_attach(task); if (ret) goto out_unlock; ret = security_task_setscheduler(task); @@ -2235,11 +2244,31 @@ static int cpuset_can_attach(struct cgro goto out_unlock; if (dl_task(task)) { - cs->nr_deadline_tasks++; - cpuset_attach_old_cs->nr_deadline_tasks--; + cs->nr_migrate_dl_tasks++; + cs->sum_migrate_dl_bw += task->dl.dl_bw; } } + if (!cs->nr_migrate_dl_tasks) + goto out_success; + + if (!cpumask_intersects(oldcs->effective_cpus, cs->effective_cpus)) { + int cpu = cpumask_any_and(cpu_active_mask, cs->effective_cpus); + + if (unlikely(cpu >= nr_cpu_ids)) { + reset_migrate_dl_data(cs); + ret = -EINVAL; + goto out_unlock; + } + + ret = dl_bw_alloc(cpu, cs->sum_migrate_dl_bw); + if (ret) { + reset_migrate_dl_data(cs); + goto out_unlock; + } + } + +out_success: /* * Mark attach is in progress. This makes validate_change() fail * changes which zero cpus/mems_allowed. @@ -2263,6 +2292,14 @@ static void cpuset_cancel_attach(struct cs->attach_in_progress--; if (!cs->attach_in_progress) wake_up(&cpuset_attach_wq); + + if (cs->nr_migrate_dl_tasks) { + int cpu = cpumask_any(cs->effective_cpus); + + dl_bw_free(cpu, cs->sum_migrate_dl_bw); + reset_migrate_dl_data(cs); + } + mutex_unlock(&cpuset_mutex); } @@ -2335,6 +2372,12 @@ static void cpuset_attach(struct cgroup_ cs->old_mems_allowed = cpuset_attach_nodemask_to; + if (cs->nr_migrate_dl_tasks) { + cs->nr_deadline_tasks += cs->nr_migrate_dl_tasks; + oldcs->nr_deadline_tasks -= cs->nr_migrate_dl_tasks; + reset_migrate_dl_data(cs); + } + cs->attach_in_progress--; if (!cs->attach_in_progress) wake_up(&cpuset_attach_wq); --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -8789,8 +8789,7 @@ int cpuset_cpumask_can_shrink(const stru return ret; } -int task_can_attach(struct task_struct *p, - const struct cpumask *cs_effective_cpus) +int task_can_attach(struct task_struct *p) { int ret = 0; @@ -8803,21 +8802,9 @@ int task_can_attach(struct task_struct * * success of set_cpus_allowed_ptr() on all attached tasks * before cpus_mask may be changed. */ - if (p->flags & PF_NO_SETAFFINITY) { + if (p->flags & PF_NO_SETAFFINITY) ret = -EINVAL; - goto out; - } - if (dl_task(p) && !cpumask_intersects(task_rq(p)->rd->span, - cs_effective_cpus)) { - int cpu = cpumask_any_and(cpu_active_mask, cs_effective_cpus); - - if (unlikely(cpu >= nr_cpu_ids)) - return -EINVAL; - ret = dl_bw_alloc(cpu, p->dl.dl_bw); - } - -out: return ret; }