| Message ID | 1362529819-19076-1-git-send-email-msb@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Op 06-03-13 01:30, Mandeep Singh Baines schreef: > This check is turning up a lot of code paths which need to be > fixed so while those paths are fixed, let's make this check > optional so that folks can still use lockdep. I think the config option should be inverted, and make it more clear that you're not just not reporting some real bugs by disabling a check that should be on by default. > CC: Tejun Heo <tj@kernel.org> > CC: Jeff Layton <jlayton@redhat.com> > CC: "Myklebust, Trond" <Trond.Myklebust@netapp.com> > CC: Oleg Nesterov <oleg@redhat.com> > CC: Ming Lei <ming.lei@canonical.com> > CC: "Rafael J. Wysocki" <rjw@sisk.pl> > CC: Andrew Morton <akpm@linux-foundation.org> > CC: Ingo Molnar <mingo@redhat.com> > --- > include/linux/freezer.h | 2 ++ > lib/Kconfig.debug | 12 ++++++++++++ > 2 files changed, 14 insertions(+) > > diff --git a/include/linux/freezer.h b/include/linux/freezer.h > index 043a5cf..03bdc54 100644 > --- a/include/linux/freezer.h > +++ b/include/linux/freezer.h > @@ -49,8 +49,10 @@ extern void thaw_kernel_threads(void); > > static inline bool try_to_freeze(void) > { > +#ifdef CONFIG_DEBUG_LOCK_HELD_FREEZING > if (!(current->flags & PF_NOFREEZE)) > debug_check_no_locks_held(); > +#endif > might_sleep(); > if (likely(!freezing(current))) > return false; > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 28be08c..bddda5f 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -547,6 +547,18 @@ config DEBUG_MUTEXES > This feature allows mutex semantics violations to be detected and > reported. > > +config DEBUG_LOCK_HELD_FREEZING > + bool "Lock debugging: detect when locks are held during freeze" > + depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT > + select DEBUG_SPINLOCK > + select DEBUG_MUTEXES > + select LOCKDEP > + help > + This feature will check whether any lock is incorrectly held > + while freezing. If a task freezes with a lock held it will > + block any other task that is waiting on that lock from freezing. > + In the case of cgroup_freezer, this can cause a deadlock. > + > config DEBUG_LOCK_ALLOC > bool "Lock debugging: detect incorrect freeing of live locks" > depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/freezer.h b/include/linux/freezer.h index 043a5cf..03bdc54 100644 --- a/include/linux/freezer.h +++ b/include/linux/freezer.h @@ -49,8 +49,10 @@ extern void thaw_kernel_threads(void); static inline bool try_to_freeze(void) { +#ifdef CONFIG_DEBUG_LOCK_HELD_FREEZING if (!(current->flags & PF_NOFREEZE)) debug_check_no_locks_held(); +#endif might_sleep(); if (likely(!freezing(current))) return false; diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 28be08c..bddda5f 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -547,6 +547,18 @@ config DEBUG_MUTEXES This feature allows mutex semantics violations to be detected and reported. +config DEBUG_LOCK_HELD_FREEZING + bool "Lock debugging: detect when locks are held during freeze" + depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select DEBUG_SPINLOCK + select DEBUG_MUTEXES + select LOCKDEP + help + This feature will check whether any lock is incorrectly held + while freezing. If a task freezes with a lock held it will + block any other task that is waiting on that lock from freezing. + In the case of cgroup_freezer, this can cause a deadlock. + config DEBUG_LOCK_ALLOC bool "Lock debugging: detect incorrect freeing of live locks" depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT