cpumask: tsk_cpumask for accessing the struct task_struct's cpus_allowed. This allows us to change the representation (to a dangling bitmap) without breaking all the callers: they can use tsk_cpumask() now and won't see a difference as the changes roll into linux-next. Signed-off-by: Rusty Russell --- include/linux/sched.h | 3 +++ kernel/fork.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/include/linux/sched.h b/include/linux/sched.h --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1401,6 +1401,9 @@ struct task_struct { unsigned long trace; #endif }; + +/* Future-safe accessor for struct task_struct's cpus_allowed. */ +#define tsk_cpumask(tsk) (&(tsk)->cpus_allowed) /* * Priority of a process goes from 0..MAX_PRIO-1, valid RT diff --git a/kernel/fork.c b/kernel/fork.c --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1212,7 +1212,7 @@ static struct task_struct *copy_process( * to ensure it is on a valid CPU (and if not, just force it back to * parent's CPU). This avoids alot of nasty races. */ - p->cpus_allowed = current->cpus_allowed; + cpumask_copy(tsk_cpumask(p), tsk_cpumask(current)); p->rt.nr_cpus_allowed = current->rt.nr_cpus_allowed; if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) || !cpu_online(task_cpu(p))))