diff options
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | kernel/cpuset.c | 13 | ||||
| -rw-r--r-- | kernel/sched/core.c | 70 | ||||
| -rw-r--r-- | kernel/sched/deadline.c | 25 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 19 |
5 files changed, 97 insertions, 32 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 5e344bbe63ec..1d1fa081d44f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2052,6 +2052,8 @@ static inline void tsk_restore_flags(struct task_struct *task, task->flags |= orig_flags & flags; } +extern int task_can_attach(struct task_struct *p, + const struct cpumask *cs_cpus_allowed); #ifdef CONFIG_SMP extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 1f107c74087b..7af8577fc8f8 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1429,17 +1429,8 @@ static int cpuset_can_attach(struct cgroup_subsys_state *css, goto out_unlock; cgroup_taskset_for_each(task, tset) { - /* - * Kthreads which disallow setaffinity shouldn't be moved - * to a new cpuset; we don't want to change their cpu - * affinity and isolating such threads by their set of - * allowed nodes is unnecessary. Thus, cpusets are not - * applicable for such threads. This prevents checking for - * success of set_cpus_allowed_ptr() on all attached tasks - * before cpus_allowed may be changed. - */ - ret = -EINVAL; - if (task->flags & PF_NO_SETAFFINITY) + ret = task_can_attach(task, cs->cpus_allowed); + if (ret) goto out_unlock; ret = security_task_setscheduler(task); if (ret) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5c067fd66db9..9993feeb8b10 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2034,25 +2034,6 @@ static inline int dl_bw_cpus(int i) } #endif -static inline -void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw) -{ - dl_b->total_bw -= tsk_bw; -} - -static inline -void __dl_add(struct dl_bw *dl_b, u64 tsk_bw) -{ - dl_b->total_bw += tsk_bw; -} - -static inline -bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) -{ - return dl_b->bw != -1 && - dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw; -} - /* * We must be sure that accepting a new task (or allowing changing the * parameters of an existing one) is consistent with the bandwidth @@ -4669,6 +4650,57 @@ void init_idle(struct task_struct *idle, int cpu) #endif } +int task_can_attach(struct task_struct *p, + const struct cpumask *cs_cpus_allowed) +{ + int ret = 0; + + /* + * Kthreads which disallow setaffinity shouldn't be moved + * to a new cpuset; we don't want to change their cpu + * affinity and isolating such threads by their set of + * allowed nodes is unnecessary. Thus, cpusets are not + * applicable for such threads. This prevents checking for + * success of set_cpus_allowed_ptr() on all attached tasks + * before cpus_allowed may be changed. + */ + if (p->flags & PF_NO_SETAFFINITY) { + ret = -EINVAL; + goto out; + } + +#ifdef CONFIG_SMP + if (dl_task(p) && !cpumask_intersects(task_rq(p)->rd->span, + cs_cpus_allowed)) { + unsigned int dest_cpu = cpumask_any_and(cpu_active_mask, + cs_cpus_allowed); + struct dl_bw *dl_b = dl_bw_of(dest_cpu); + bool overflow; + int cpus; + unsigned long flags; + + raw_spin_lock_irqsave(&dl_b->lock, flags); + cpus = dl_bw_cpus(dest_cpu); + overflow = __dl_overflow(dl_b, cpus, 0, p->dl.dl_bw); + if (overflow) + ret = -EBUSY; + else { + /* + * We reserve space for this task in the destination + * root_domain, as we can't fail after this point. + * We will free resources in the source root_domain + * later on (see set_cpus_allowed_dl()). + */ + __dl_add(dl_b, p->dl.dl_bw); + } + raw_spin_unlock_irqrestore(&dl_b->lock, flags); + + } +#endif +out: + return ret; +} + #ifdef CONFIG_SMP /* * move_queued_task - move a queued task to new rq. diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 9d1e76a21297..8aaa971ffecd 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1517,10 +1517,33 @@ static void set_cpus_allowed_dl(struct task_struct *p, const struct cpumask *new_mask) { struct rq *rq; + struct root_domain *src_rd; int weight; BUG_ON(!dl_task(p)); + rq = task_rq(p); + src_rd = rq->rd; + /* + * Migrating a SCHED_DEADLINE task between exclusive + * cpusets (different root_domains) entails a bandwidth + * update. We already made space for us in the destination + * domain (see cpuset_can_attach()). + */ + if (!cpumask_intersects(src_rd->span, new_mask)) { + struct dl_bw *src_dl_b; + + src_dl_b = dl_bw_of(cpu_of(rq)); + /* + * We now free resources of the root_domain we are migrating + * off. In the worst case, sched_setattr() may temporary fail + * until we complete the update. + */ + raw_spin_lock(&src_dl_b->lock); + __dl_clear(src_dl_b, p->dl.dl_bw); + raw_spin_unlock(&src_dl_b->lock); + } + /* * Update only if the task is actually running (i.e., * it is on the rq AND it is not throttled). @@ -1537,8 +1560,6 @@ static void set_cpus_allowed_dl(struct task_struct *p, if ((p->nr_cpus_allowed > 1) == (weight > 1)) return; - rq = task_rq(p); - /* * The process used to be able to migrate OR it can now migrate */ diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 57aacea1cbdf..ec3917c5f898 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -176,6 +176,25 @@ struct dl_bw { u64 bw, total_bw; }; +static inline +void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw) +{ + dl_b->total_bw -= tsk_bw; +} + +static inline +void __dl_add(struct dl_bw *dl_b, u64 tsk_bw) +{ + dl_b->total_bw += tsk_bw; +} + +static inline +bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) +{ + return dl_b->bw != -1 && + dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw; +} + extern struct mutex sched_domains_mutex; #ifdef CONFIG_CGROUP_SCHED |