From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Marc Zyngier <maz@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Qais Yousef <qais.yousef@arm.com>,
Suren Baghdasaryan <surenb@google.com>,
Quentin Perret <qperret@google.com>, Tejun Heo <tj@kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Valentin Schneider <valentin.schneider@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
kernel-team@android.com
Subject: [PATCH v10 09/16] sched: Introduce dl_task_check_affinity() to check proposed affinity
Date: Wed, 23 Jun 2021 18:38:41 +0100 [thread overview]
Message-ID: <20210623173848.318-10-will@kernel.org> (raw)
In-Reply-To: <20210623173848.318-1-will@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 <bristot@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
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)
--
2.32.0.93.g670b81a890-goog
next prev parent reply other threads:[~2021-06-23 17:39 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-23 17:38 [PATCH v10 00/16] Add support for 32-bit tasks on asymmetric AArch32 systems Will Deacon
2021-06-23 17:38 ` [PATCH v10 01/16] sched: Introduce task_cpu_possible_mask() to limit fallback rq selection Will Deacon
2021-06-23 17:38 ` [PATCH v10 02/16] cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 Will Deacon
2021-06-23 17:38 ` [PATCH v10 03/16] cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() Will Deacon
2021-06-23 17:38 ` [PATCH v10 04/16] cpuset: Cleanup cpuset_cpus_allowed_fallback() use in select_fallback_rq() Will Deacon
2021-06-23 17:38 ` [PATCH v10 05/16] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Will Deacon
2021-06-23 17:38 ` [PATCH v10 06/16] sched: Introduce task_struct::user_cpus_ptr to track requested affinity Will Deacon
2021-06-23 17:38 ` [PATCH v10 07/16] sched: Split the guts of sched_setaffinity() into a helper function Will Deacon
2021-06-23 17:38 ` [PATCH v10 08/16] sched: Allow task CPU affinity to be restricted on asymmetric systems Will Deacon
2021-06-23 17:38 ` Will Deacon [this message]
2021-06-23 17:38 ` [PATCH v10 10/16] arm64: Implement task_cpu_possible_mask() Will Deacon
2021-06-23 17:38 ` [PATCH v10 11/16] arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 Will Deacon
2021-06-23 17:38 ` [PATCH v10 12/16] arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system Will Deacon
2021-06-23 17:38 ` [PATCH v10 13/16] arm64: Advertise CPUs capable of running 32-bit applications in sysfs Will Deacon
2021-06-25 8:46 ` Greg Kroah-Hartman
2021-06-25 9:36 ` Will Deacon
2021-06-25 9:49 ` Greg Kroah-Hartman
2021-06-23 17:38 ` [PATCH v10 14/16] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Will Deacon
2021-06-23 17:38 ` [PATCH v10 15/16] arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores Will Deacon
2021-06-23 17:38 ` [PATCH v10 16/16] Documentation: arm64: describe asymmetric 32-bit support Will Deacon
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