From: "tip-bot2 for Will Deacon" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Will Deacon <will@kernel.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Valentin Schneider <Valentin.Schneider@arm.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: sched/core] sched: Introduce task_struct::user_cpus_ptr to track requested affinity
Date: Mon, 23 Aug 2021 09:26:21 -0000 [thread overview]
Message-ID: <162971078187.25758.12447255888299814756.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20210730112443.23245-7-will@kernel.org>
The following commit has been merged into the sched/core branch of tip:
Commit-ID: b90ca8badbd11488e5f762346b028666808164e7
Gitweb: https://git.kernel.org/tip/b90ca8badbd11488e5f762346b028666808164e7
Author: Will Deacon <will@kernel.org>
AuthorDate: Fri, 30 Jul 2021 12:24:33 +01:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 20 Aug 2021 12:33:00 +02:00
sched: Introduce task_struct::user_cpus_ptr to track requested affinity
In preparation for saving and restoring the user-requested CPU affinity
mask of a task, add a new cpumask_t pointer to 'struct task_struct'.
If the pointer is non-NULL, then the mask is copied across fork() and
freed on task exit.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-7-will@kernel.org
---
include/linux/sched.h | 13 +++++++++++++
init/init_task.c | 1 +
kernel/fork.c | 2 ++
kernel/sched/core.c | 20 ++++++++++++++++++++
4 files changed, 36 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 50db949..2c5d638 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -748,6 +748,7 @@ struct task_struct {
unsigned int policy;
int nr_cpus_allowed;
const cpumask_t *cpus_ptr;
+ cpumask_t *user_cpus_ptr;
cpumask_t cpus_mask;
void *migration_pending;
#ifdef CONFIG_SMP
@@ -1706,6 +1707,8 @@ extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_
#ifdef CONFIG_SMP
extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
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);
#else
static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
{
@@ -1716,6 +1719,16 @@ static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpuma
return -EINVAL;
return 0;
}
+static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
+{
+ if (src->user_cpus_ptr)
+ return -EINVAL;
+ return 0;
+}
+static inline void release_user_cpus_ptr(struct task_struct *p)
+{
+ WARN_ON(p->user_cpus_ptr);
+}
#endif
extern int yield_to(struct task_struct *p, bool preempt);
diff --git a/init/init_task.c b/init/init_task.c
index 562f2ef..2d02406 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -80,6 +80,7 @@ struct task_struct init_task
.normal_prio = MAX_PRIO - 20,
.policy = SCHED_NORMAL,
.cpus_ptr = &init_task.cpus_mask,
+ .user_cpus_ptr = NULL,
.cpus_mask = CPU_MASK_ALL,
.nr_cpus_allowed= NR_CPUS,
.mm = NULL,
diff --git a/kernel/fork.c b/kernel/fork.c
index 1a9af73..5d7addf 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -446,6 +446,7 @@ void put_task_stack(struct task_struct *tsk)
void free_task(struct task_struct *tsk)
{
+ release_user_cpus_ptr(tsk);
scs_release(tsk);
#ifndef CONFIG_THREAD_INFO_IN_TASK
@@ -919,6 +920,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
#endif
if (orig->cpus_ptr == &orig->cpus_mask)
tsk->cpus_ptr = &tsk->cpus_mask;
+ dup_user_cpus_ptr(tsk, orig, node);
/*
* One for the user space visible state that goes away when reaped.
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8cec0d2..360a3ec 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2480,6 +2480,26 @@ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
__do_set_cpus_allowed(p, new_mask, 0);
}
+int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src,
+ int node)
+{
+ if (!src->user_cpus_ptr)
+ return 0;
+
+ dst->user_cpus_ptr = kmalloc_node(cpumask_size(), GFP_KERNEL, node);
+ if (!dst->user_cpus_ptr)
+ return -ENOMEM;
+
+ cpumask_copy(dst->user_cpus_ptr, src->user_cpus_ptr);
+ return 0;
+}
+
+void release_user_cpus_ptr(struct task_struct *p)
+{
+ kfree(p->user_cpus_ptr);
+ p->user_cpus_ptr = NULL;
+}
+
/*
* This function is wildly self concurrent; here be dragons.
*
next prev parent reply other threads:[~2021-08-23 9:26 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-30 11:24 [PATCH v11 00/16] Add support for 32-bit tasks on asymmetric AArch32 systems Will Deacon
2021-07-30 11:24 ` [PATCH v11 01/16] sched: Introduce task_cpu_possible_mask() to limit fallback rq selection Will Deacon
2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon
2021-07-30 11:24 ` [PATCH v11 02/16] cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 Will Deacon
2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon
2021-07-30 11:24 ` [PATCH v11 03/16] cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() Will Deacon
2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon
2021-07-30 11:24 ` [PATCH v11 04/16] cpuset: Cleanup cpuset_cpus_allowed_fallback() use in select_fallback_rq() Will Deacon
2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon
2021-07-30 11:24 ` [PATCH v11 05/16] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Will Deacon
2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon
2021-07-30 11:24 ` [PATCH v11 06/16] sched: Introduce task_struct::user_cpus_ptr to track requested affinity Will Deacon
2021-08-23 9:26 ` tip-bot2 for Will Deacon [this message]
2021-07-30 11:24 ` [PATCH v11 07/16] sched: Split the guts of sched_setaffinity() into a helper function Will Deacon
2021-08-17 15:40 ` Peter Zijlstra
2021-08-18 10:50 ` Will Deacon
2021-08-18 10:56 ` Peter Zijlstra
2021-08-18 11:11 ` Will Deacon
2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon
2021-07-30 11:24 ` [PATCH v11 08/16] sched: Allow task CPU affinity to be restricted on asymmetric systems Will Deacon
2021-08-17 15:10 ` Peter Zijlstra
2021-08-18 10:42 ` Will Deacon
2021-08-18 10:56 ` Peter Zijlstra
2021-08-18 11:53 ` Peter Zijlstra
2021-08-18 12:19 ` Will Deacon
2021-08-18 11:06 ` Peter Zijlstra
2021-08-17 15:41 ` Peter Zijlstra
2021-08-18 10:43 ` Will Deacon
2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon
2021-07-30 11:24 ` [PATCH v11 09/16] sched: Introduce dl_task_check_affinity() to check proposed affinity Will Deacon
2021-08-23 9:26 ` [tip: sched/core] " tip-bot2 for Will Deacon
2021-07-30 11:24 ` [PATCH v11 10/16] arm64: Implement task_cpu_possible_mask() Will Deacon
2021-07-30 11:24 ` [PATCH v11 11/16] arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 Will Deacon
2021-07-30 11:24 ` [PATCH v11 12/16] arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system Will Deacon
2021-07-30 11:24 ` [PATCH v11 13/16] arm64: Advertise CPUs capable of running 32-bit applications in sysfs Will Deacon
2021-07-30 11:24 ` [PATCH v11 14/16] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Will Deacon
2021-07-30 11:24 ` [PATCH v11 15/16] arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores Will Deacon
2021-07-30 11:24 ` [PATCH v11 16/16] Documentation: arm64: describe asymmetric 32-bit support Will Deacon
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