Re: [PATCH v2 0/4] debug_pagealloc improvements through page_owner

[Andrew Morton]

On Thu, 22 Aug 2019 16:03:44 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Tue, 20 Aug 2019 15:18:24 +0200 Vlastimil Babka <vbabka@xxxxxxx> wrote:
> 
> > v2: also fix THP split handling (added Patch 1) per Kirill
> > 
> > The debug_pagealloc functionality serves a similar purpose on the page
> > allocator level that slub_debug does on the kmalloc level, which is to detect
> > bad users. One notable feature that slub_debug has is storing stack traces of
> > who last allocated and freed the object. On page level we track allocations via
> > page_owner, but that info is discarded when freeing, and we don't track freeing
> > at all. This series improves those aspects. With both debug_pagealloc and
> > page_owner enabled, we can then get bug reports such as the example in Patch 4.
> > 
> > SLUB debug tracking additionaly stores cpu, pid and timestamp. This could be
> > added later, if deemed useful enough to justify the additional page_ext
> > structure size.
> 
> Thanks.  I split [1/1] out of the series as a bugfix and turned this
> into a three-patch series.
> 

None of which anyone has yet reviewed :(