Re: [PATCH 3/3] vmevent: Implement special low-memory attribute

From: Anton Vorontsov
Date: Tue May 08 2012 - 04:23:14 EST


On Tue, May 08, 2012 at 01:13:05AM -0700, Anton Vorontsov wrote:
> On Tue, May 08, 2012 at 03:16:59AM -0400, KOSAKI Motohiro wrote:
> [...]
> > >So, feel free to call me an idiot, but please expand your points a
> > >little bit or give a link to the discussion you're referring to?
> >
> > I don't think you are idiot. But I hope you test your patch before submitting.
> > That just don't work especially on x86. Because of, all x86 box have multiple zone
> > and summarized statistics (i.e. global_page_state() thing) don't work and can't
> > prevent oom nor swapping.
>
> Now I think I understand you: we don't take into account that e.g. DMA
> zone is not usable by the normal allocations, and so if we're basing our
> calculations on summarized stats, it is indeed possible to get an OOM
> in such a case.

Oops. Looking into it more, I think I was wrong here: kernel will surely
use pages from the DMA zone when we have no pages in normal zones.

So, I don't see how we can get OOM in that case.

Hm.

--
Anton Vorontsov
Email: cbouatmailru@xxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/