Hello, On Wed, Apr 16, 2014 at 09:41:40AM +0800, Li Zhong wrote: > > If so, that is > > an actually possible deadlock, no? > > Yes, but it seems to me that it is solved in commit 5e33bc41, which uses > lock_device_hotplug_sysfs() to return a restart syscall error if not > able to try lock the device_hotplug_lock. That also requires the device > removing code path to take the device_hotplug_lock.
But that patch only takes out device_hotplug_lock out of the dependency graph and does nothing for cpu_add_remove_lock. It seems to be that there still is a deadlock condition involving s_active and cpu_add_remove_lock. Am I missing something here? Now that kernfs has a proper mechanism to deal with it, wouldn't it make more sense to replace 5e33bc41 with prper s_active protection breaking? Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
