Re: [RFC PATCH 0/3] Aggressively allocate the pages on cma reserved memory

From: Mel Gorman
Date: Thu May 15 2014 - 05:47:32 EST


On Thu, May 15, 2014 at 11:10:55AM +0900, Joonsoo Kim wrote:
> > That doesn't always prefer CMA region. It would be nice to
> > understand why grouping in pageblock_nr_pages is beneficial. Also in
> > your patch you decrement nr_try_cma for every 'order' allocation. Why ?
>
> pageblock_nr_pages is just magic value with no rationale. :)

I'm not following this discussions closely but there is rational to that
value -- it's the size of a huge page for that architecture. At the time
the fragmentation avoidance was implemented this was the largest allocation
size of interest.

--
Mel Gorman
SUSE Labs
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