[Linaro-mm-sig] [PATCH 11/15] mm: trigger page reclaim in alloc_contig_range() to stabilize watermarks

[Michal Nazarewicz]

On Wed, 08 Feb 2012 03:04:18 +0100, sandeep patil <psandeep.s at gmail.com> wrote:
> There's another problem I am facing with zone watermarks and CMA.
>
> Test details:
> Memory  : 480 MB of total memory, 128 MB CMA region
> Test case : around 600 MB of file transfer over USB RNDIS onto target
> System Load : ftpd with console running on target.
> No one is doing CMA allocations except for the DMA allocations done by the
> drivers.
>
> Result : After about 300MB transfer, I start getting GFP_ATOMIC
> allocation failures.  This only happens if CMA region is reserved.

[...]

> Total memory available is way above the zone watermarks. So, we ended
> up starving
> UNMOVABLE/RECLAIMABLE atomic allocations that cannot fallback on CMA region.

This looks like something Mel warned me about.  I don't really have a good
solution for that yet. ;/

-- 
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..o | Computer Science,  Michał “mina86” Nazarewicz    (o o)
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