Some system such as powerpc, some tsk (vcpu thread) can only run on the dedicated cpu. Since we adapt some asymmetric method to monitor the whole physical cpu. (powerKVM only allows the primary hwthread to set up runtime env for the secondary when entering guest). Nowadays, powerKVM run with all the secondary hwthread offline to ensure the vcpu threads only run on the primary thread. But we plan to keep all cpus online when running powerKVM to give more power when switching back to host, so introduce sys_allowed cpumask to reflect the cpuset which the vcpu thread can run on. Signed-off-by: Liu Ping Fan <pingfank@xxxxxxxxxxxxxxxxxx> --- include/linux/init_task.h | 1 + include/linux/sched.h | 6 ++++++ kernel/sched/core.c | 10 ++++++++-- 3 files changed, 15 insertions(+), 2 deletions(-) diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 2bb4c4f3..c56f69e 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -172,6 +172,7 @@ extern struct task_group root_task_group; .normal_prio = MAX_PRIO-20, \ .policy = SCHED_NORMAL, \ .cpus_allowed = CPU_MASK_ALL, \ + .sys_allowed = CPU_MASK_ALL, \ .nr_cpus_allowed= NR_CPUS, \ .mm = NULL, \ .active_mm = &init_mm, \ diff --git a/include/linux/sched.h b/include/linux/sched.h index 5c2c885..ce429f3 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1260,7 +1260,10 @@ struct task_struct { unsigned int policy; int nr_cpus_allowed; + /* Anded user and sys_allowed */ cpumask_t cpus_allowed; + /* due to the feature of asymmetric, some tsk can only run on such cpu */ + cpumask_t sys_allowed; #ifdef CONFIG_PREEMPT_RCU int rcu_read_lock_nesting; @@ -2030,6 +2033,9 @@ static inline void tsk_restore_flags(struct task_struct *task, } #ifdef CONFIG_SMP +extern void set_cpus_sys_allowed(struct task_struct *p, + const struct cpumask *new_mask); + extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ec1a286..2cd1ae3 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4596,13 +4596,19 @@ void init_idle(struct task_struct *idle, int cpu) } #ifdef CONFIG_SMP +void set_cpus_sys_allowed(struct task_struct *p, + const struct cpumask *new_mask) +{ + cpumask_copy(&p->sys_allowed, new_mask); +} + void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) { if (p->sched_class && p->sched_class->set_cpus_allowed) p->sched_class->set_cpus_allowed(p, new_mask); - cpumask_copy(&p->cpus_allowed, new_mask); - p->nr_cpus_allowed = cpumask_weight(new_mask); + cpumask_and(&p->cpus_allowed, &p->sys_allowed, new_mask); + p->nr_cpus_allowed = cpumask_weight(&p->cpus_allowed); } /* -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html