Messages in this thread | | | Date | Thu, 21 Feb 2013 13:42:27 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH v6] lockdep: check that no locks held at freeze time |
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On Thu, 21 Feb 2013 08:51:41 -0800 Mandeep Singh Baines <msb@chromium.org> wrote:
> 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. > > ... > > --- a/include/linux/freezer.h > +++ b/include/linux/freezer.h > > ... > > @@ -43,6 +44,8 @@ extern void thaw_kernel_threads(void); > > static inline bool try_to_freeze(void) > { > + if (!(current->flags & PF_NOFREEZE)) > + debug_check_no_locks_held(); > might_sleep(); > if (likely(!freezing(current))) > return false; > > ... >
It still needs http://ozlabs.org/~akpm/mmots/broken-out/lockdep-check-that-no-locks-held-at-freeze-time-fix.patch
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