Re: [PATCH 2/2] mm/page_alloc: DEBUG_VM checks for free_list placement of CMA and RESERVE pages

Andrew Morton
2014-05-08T22:34:37Z

On Thu, 8 May 2014 15:19:37 +0900 Minchan Kim <minchan@kernel.org> wrote:

> > I also think that VM_DEBUG overhead isn't problem because of same
> > reason from Vlastimil.
>
> Guys, please read this.
>
> https://lkml.org/lkml/2013/7/17/591
>
> If you guys really want it, we could separate it with
> CONFIG_DEBUG_CMA or CONFIG_DEBUG_RESERVE like stuff.
> Otherwise, just remain in mmotm.

Wise words, those.

Yes, these checks are in a pretty hot path. I'm inclined to make the
patch -mm (and -next) only.

Unless there's a really good reason, such as "nobody who uses CMA is
likely to be testing -next", which sounds likely :(