Re: [PATCH 2/3] page allocator: Do not allow interrupts to use ALLOC_HARDER

David Rientjes
2009-10-31T19:51:24Z

On Sat, 31 Oct 2009, Pavel Machek wrote:

> > Giving rt tasks access to memory reserves is necessary to reduce latency,
> > the privilege does not apply to interrupts that subsequently get run on
> > the same cpu.
>
> If rt task needs to allocate memory like that, then its broken,
> anyway...
>

Um, no, it's a matter of the kernel implementation. We allow such tasks
to allocate deeper into reserves to avoid the page allocator from
incurring a significant penalty when direct reclaim is required.
Background reclaim has already commenced at this point in the slowpath.