On Thu, Jun 19, 2014 at 10:37:17PM +0200, Thomas Gleixner wrote: > On Thu, 19 Jun 2014, Paul E. McKenney wrote: > > On Thu, Jun 19, 2014 at 09:29:08PM +0200, Thomas Gleixner wrote: > > > On Thu, 19 Jun 2014, Paul E. McKenney wrote: > > > Well, no. Look at the callchain: > > > > > > __call_rcu > > > debug_object_activate > > > rcuhead_fixup_activate > > > debug_object_init > > > kmem_cache_alloc > > > > > > So call rcu activates the object, but the object has no reference in > > > the debug objects code so the fixup code is called which inits the > > > object and allocates a reference .... > > > > OK, got it. And you are right, call_rcu() has done this for a very > > long time, so not sure what changed. But it seems like the right > > approach is to provide a debug-object-free call_rcu_alloc() for use > > by the memory allocators. > > > > Seem reasonable? If so, please see the following patch. > > Not really, you're torpedoing the whole purpose of debugobjects :) > > So, why can't we just init the rcu head when the stuff is created? That would allow me to keep my code unchanged, so I am in favor. ;-) Thanx, Paul > If that's impossible due to other memory allocator constraints, then > instead of inventing a whole new API we can simply flag the relevent > data in the memory allocator as we do with the debug objects mem cache > itself (SLAB_DEBUG_OBJECTS). > > Thanks, > > tglx > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>