Re: [PATCH] check_for_tasks: read_lock(tasklist_lock) doesn't need to disable irqs

Kirill Tkhai
2015-09-10T13:31:40Z

On 10.09.2015 16:07, Oleg Nesterov wrote:
> check_for_tasks() doesn't need to disable irqs, recursive read_lock()
> from interrupt is fine.
>
> While at it, s/do_each_thread/for_each_process_thread/.
>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Reviewed-by: Kirill Tkhai <ktkhai@odin.com>

> ---
> kernel/cpu.c | 8 ++++----
> 1 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/cpu.c b/kernel/cpu.c
> index 94bbe46..24551f2 100644
> --- a/kernel/cpu.c
> +++ b/kernel/cpu.c
> @@ -302,8 +302,8 @@ static inline void check_for_tasks(int dead_cpu)
> {
> struct task_struct *g, *p;
>
> - read_lock_irq(&tasklist_lock);
> - do_each_thread(g, p) {
> + read_lock(&tasklist_lock);
> + for_each_process_thread(g, p) {
> if (!p->on_rq)
> continue;
> /*
> @@ -318,8 +318,8 @@ static inline void check_for_tasks(int dead_cpu)
>
> pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n",
> p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags);
> - } while_each_thread(g, p);
> - read_unlock_irq(&tasklist_lock);
> + }
> + read_unlock(&tasklist_lock);
> }
>
> struct take_cpu_down_param {
>