Re: [PATCH v2 7/7] mm/page_owner: correct owner information for early allocated pages

From: Andrew Morton
Date: Fri Nov 21 2014 - 18:38:48 EST

On Fri, 21 Nov 2014 17:14:06 +0900 Joonsoo Kim <> wrote:

> Extended memory to store page owner information is initialized some time
> later than that page allocator starts. Until initialization, many pages
> can be allocated and they have no owner information. This make debugging
> using page owner harder, so some fixup will be helpful.
> This patch fix up this situation by setting fake owner information
> immediately after page extension is initialized. Information doesn't
> tell the right owner, but, at least, it can tell whether page is
> allocated or not, more correctly.
> On my testing, this patch catches 13343 early allocated pages, although
> they are mostly allocated from page extension feature. Anyway, after then,
> there is no page left that it is allocated and has no page owner flag.

We really should have a Documentation/vm/page_owner.txt which explains
all this stuff, provides examples, etc.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at