Re: [RFC 7/7] Switch of PF_MEMALLOC during writeout

From: Andi Kleen
Date: Mon Aug 20 2007 - 18:14:46 EST


Christoph Lameter <clameter@xxxxxxx> writes:

> Switch off PF_MEMALLOC during both direct and kswapd reclaim.
>
> This works because we are not holding any locks at that point because
> reclaim is essentially complete. The write occurs when the memory on
> the zones is at the high water mark so it is unlikely that writeout
> will get into trouble. If so then reclaim can be called recursively to
> reclaim more pages.

What would stop multiple recursions in extreme low memory cases? Seems
risky to me and risking stack overflow. Perhaps define another flag to catch that?

-Andi
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