Re: [RFC] [RFT] [PATCH] memory zone balancing

Rik van Riel
2000-01-04T03:23:31Z

On Mon, 3 Jan 100, Kanoj Sarcar wrote:

> Okay, here is a reworked version. Note that this version does not
> do per-zone balancing, since experiments show that we need to tune
> per-zone watermarks properly before we can start doing that. I am
> working on coming up with a good estimate of per-zone watermarks.
> Basically, I am trying to answer the question: if there are d dmapages,
> r regular pages and h highmem pages, for a total of d+r+h pages,
> what should the watermarks be for each zone?

d+r+h > limit
d > limit/2
r > limit/4
h > limit/8

DMA pages should always be present, regular pages for
storing pagetables and stuff need to be there too, higmem
pages we don't really care about.

Btw, I think we probably want to increase freepages.min
to 512 or even more on machines that have >1GB of memory.
The current limit of 256 was really intended for machines
with a single zone of memory...

(but on <1GB machines I don't know if it makes sense to
raise the limit much more ... maybe we should raise the
limit automagically if the page alloc/io rate is too
high?)

regards,

Rik
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