Re: CMA and zone watermarks

Marek Szyprowski
2012-10-09T00:37:24Z

Hello,

On 10/8/2012 5:41 PM, Rabin Vincent wrote:

> It appears that when CMA is enabled, the zone watermarks are not properly
> respected, leading to for example GFP_NOWAIT allocations getting access to the
> high pools.
>
> I ran the following test code which simply allocates pages with GFP_NOWAIT
> until it fails, and then tries GFP_ATOMIC. Without CMA, the GFP_ATOMIC
> allocation succeeds, with CMA, it fails too.

Could You run your test with latest linux-next kernel? There have been
some patches merged to akpm tree which should fix accounting for free
and free cma pages. I hope it should fix this issue.

Best regards
--
Marek Szyprowski
Samsung Poland R&D Center