Messages in this thread | | | Date | Sat, 4 May 2013 15:04:40 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH 2/2] lockdep: check that no locks held at freeze time |
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On Fri 2013-05-03 14:04:10, Colin Cross wrote: > From: Mandeep Singh Baines <msb@chromium.org> > > We shouldn't try_to_freeze if locks are held. Holding a lock can cause a > deadlock if the lock is later acquired in the suspend or hibernate path > (e.g. by dpm). Holding a lock can also cause a deadlock in the case of > cgroup_freezer if a lock is held inside a frozen cgroup that is later > acquired by a process outside that group.
Ok, but this does not explain why
> --- a/include/linux/debug_locks.h > +++ b/include/linux/debug_locks.h > @@ -51,7 +51,7 @@ struct task_struct; > extern void debug_show_all_locks(void); > extern void debug_show_held_locks(struct task_struct *task); > extern void debug_check_no_locks_freed(const void *from, unsigned long len); > -extern void debug_check_no_locks_held(struct task_struct *task); > +extern void debug_check_no_locks_held(void); > #else > static inline void debug_show_all_locks(void) > {
Removing task_struct argument from those functions is good idea?
> --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -835,7 +835,7 @@ void do_exit(long code) > /* > * Make sure we are holding no locks: > */ > - debug_check_no_locks_held(tsk); > + debug_check_no_locks_held();
Is task guaranteed == current?
Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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