On Thu, Oct 18, 2012 at 09:20:20AM -0400, Steven Rostedt wrote: > On Thu, Oct 11, 2012 at 09:59:16AM +0900, Greg Kroah-Hartman wrote: > > 3.4-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Michael Wang <wang...@linux.vnet.ibm.com> > > > > commit 947ca1856a7e60aa6d20536785e6a42dff25aa6e upstream. > > > > DEADLOCK will be report while running a kernel with NUMA and LOCKDEP > > enabled, > > the process of this fake report is: > > > > kmem_cache_free() //free obj in cachep > > -> cache_free_alien() //acquire cachep's l3 alien lock > > -> __drain_alien_cache() > > -> free_block() > > -> slab_destroy() > > -> kmem_cache_free() //free slab in cachep->slabp_cache > > -> cache_free_alien() //acquire cachep->slabp_cache's l3 alien lock > > > > Since the cachep and cachep->slabp_cache's l3 alien are in the same lock > > class, > > fake report generated. > > > > This should not happen since we already have init_lock_keys() which will > > reassign the lock class for both l3 list and l3 alien. > > > > However, init_lock_keys() was invoked at a wrong position which is before we > > invoke enable_cpucache() on each cache. > > > > Since until set slab_state to be FULL, we won't invoke enable_cpucache() > > on caches to build their l3 alien while creating them, so although we > > invoked > > init_lock_keys(), the l3 alien lock class won't change since we don't have > > them until invoked enable_cpucache() later. > > > > This patch will invoke init_lock_keys() after we done enable_cpucache() > > instead of before to avoid the fake DEADLOCK report. > > > > Michael traced the problem back to a commit in release 3.0.0: > > I don't see this fix in the last 3.0 stable release. Shouldn't it go > there too?
As-is, it doesn't apply at all. If someone provides me a backport, I'll be glad to apply it there. thanks, greg k-h -- 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/
