Re: [PATCH 1/5] vfork: don't freezer_count() for in-kernel usersof CLONE_VFORK

From: Oleg Nesterov
Date: Fri Feb 15 2013 - 10:30:07 EST

On 02/14, Mandeep Singh Baines wrote:
> We don't need to call freezer_do_not_count() for in-kernel users
> of CLONE_VFORK since exec will get called in bounded time.


> We don't want to call freezer_count() for in-kernel users because
> they may be holding locks.

Who? We should not do this anyway. And __call_usermodehelper() doesn't

OK, its caller (process_one_work) does lock_map_acquire() for debugging
purposes, this can "confuse" print_held_locks_bug(). But this thread is

> @@ -722,9 +722,11 @@ static int wait_for_vfork_done(struct task_struct *child,
> {
> int killed;
> - freezer_do_not_count();
> + if (current->mm)
> + freezer_do_not_count();

And if you want to exclude in-kernel users, then perhaps PF_KTHREAD check
will look a bit better.


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