Re: [RFC][PATCH 0/3] Speed up SLUB poisoning + disable checks

From: Joonsoo Kim
Date: Tue Jan 26 2016 - 10:21:41 EST

2016-01-27 0:01 GMT+09:00 Christoph Lameter <cl@xxxxxxxxx>:
> On Tue, 26 Jan 2016, Joonsoo Kim wrote:
>> I doesn't follow up that discussion, but, I think that reusing
>> SLAB_POISON for slab sanitization needs more changes. I assume that
>> completeness and performance is matter for slab sanitization.
>> 1) SLAB_POISON isn't applied to specific kmem_cache which has
>> constructor or SLAB_DESTROY_BY_RCU flag. For debug, it's not necessary
>> to be applied, but, for slab sanitization, it is better to apply it to
>> all caches.
> Those slabs can be legitimately accessed after the objects were freed. You
> cannot sanitize nor poison.

Oops... you are right. I misunderstand what SLAB_DESTROY_BY_RCU is.
Now, it's clear to me.