Messages in this thread | | | Date | Mon, 11 Mar 2013 18:36:25 +0100 | From | Oleg Nesterov <> | Subject | [PATCH 0/2] kthread: kill task_get_live_kthread() |
| |
Hello.
Imho, task_get_live_kthread() is very confusing and unneeded. 2a1d4460 copied get_task_struct() + "vfork_done != NULL" from kthread_stop(), but only kthread_stop() needs them both.
It needs get_task_struct() because kthread_stop() can be used when the caller doesn't have a reference but we know that this thread can't exit itself.
At the same time, if it can exit we do not need get_task_struct() (the caller must have a reference) but we need to ensure we do not use to_kthread(NULL) if it has exited.
I think that kthread_park/unpark can simply use to_kthread(), but this series only removes get_task_struct() and keeps "alive" check.
But the actual reason for this cleanup is that I do not understand why park/unpark abuse kthread.c.
Thomas, can't we move kthread->parked/cpu to smpboot_thread_data and move all this code into kernel/smpboot.c? Just for example, why kthread() does __kthread_parkme() ? smpboot_thread_fn() can do this at the start.
Or this would be wrong/undesirable by some reason?
Oleg.
| |