Re: [PATCH v2 tip/core/rcu 01/11] mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU

From: David Rientjes
Date: Mon Apr 17 2017 - 20:14:46 EST


On Mon, 17 Apr 2017, 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.
>
> However, there is a phrase for this, namely "type safety". This commit
> therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order
> to avoid future instances of this sort of confusion.
>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> Cc: Christoph Lameter <cl@xxxxxxxxx>
> Cc: Pekka Enberg <penberg@xxxxxxxxxx>
> Cc: David Rientjes <rientjes@xxxxxxxxxx>
> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: <linux-mm@xxxxxxxxx>
> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
> [ paulmck: Add comments mentioning the old name, as requested by Eric
> Dumazet, in order to help people familiar with the old name find
> the new one. ]

Acked-by: David Rientjes <rientjes@xxxxxxxxxx>