Re: + syscalls-x86-add-__nr_kcmp-syscall-v8.patch added to -mm tree

[Oleg Nesterov]

On 02/16, Vasiliy Kulikov wrote:
>
> On Thu, Feb 16, 2012 at 20:49 +0400, Cyrill Gorcunov wrote:
> > +	err = mutex_lock_killable(m1);
> > +	if (!err && likely(m1 != m2)) {
> > +		err = mutex_lock_killable_nested(m2, SINGLE_DEPTH_NESTING);
>
> Doesn't it lead to a deadlock?
>
> mutex_lock_killable(task1)
> |					mutex_lock_killable(task2)
> mutex_lock_killable_nested(task2)	|
> (locked)				|
> 					mutex_lock_killable_nested(task1)
> 					(locked)

Please note the

	if (m1 >= m2)
		swap(m1. m2)

at the start.

Oleg.

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