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

[Andrew Morton]

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.