On Thu, Apr 13, 2017 at 06:17:09PM +0200, Peter Zijlstra wrote: > On Thu, Apr 13, 2017 at 01:06:56PM +0200, Vlastimil Babka wrote: > > On 04/13/2017 11:12 AM, Peter Zijlstra wrote: > > > On Wed, Apr 12, 2017 at 09:55:37AM -0700, Paul E. McKenney wrote: > > >> A group of Linux kernel hackers reported chasing a bug that resulted > > >> from their assumption that SLAB_DESTROY_BY_RCU provided an existence > > >> guarantee, that is, that no block from such a slab would be reallocated > > >> during an RCU read-side critical section. Of course, that is not the > > >> case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire > > >> slab of blocks. > > > > > > And that while we wrote a huge honking comment right along with it... > > > > > >> [ paulmck: Add "tombstone" comments as requested by Eric Dumazet. ] > > > > > > I cannot find any occurrence of "tomb" or "TOMB" in the actual patch, > > > confused? > > > > It's the comments such as: > > > > + * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU. > > > > so that people who remember the old name can git grep its fate. > > git log -S SLAB_DESTROY_BY_RCU My (perhaps naive) hope is that having more than one path to the information will reduce the number of "Whatever happened to SLAB_DESTROY_BY_RCU?" queries. Thanx, Paul -- 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>
