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Re: [XenPPC] [RFC] 64mb Chunk Allocator

On Jun 26, 2006, at 12:31 PM, Hollis Blanchard wrote:

On Sat, 2006-06-24 at 16:31 -0400, Dan E Poff wrote:

On Thu, 2006-06-22 at 16:56 -0400, Michal Ostrowski wrote:
How is this expected to be integrated into existing memory
allocators in Xen?

As I understand Jimi's approach, all of physical memory would be
divided into 64mb chunks.

Dan, it would be good if the size of the chunk was a parameter, for the init phase, it doesn't need to be at first but on other chips the RMA is less restrictive, and even when RMA issues go away it may prove useful to use "chunks" with large page granularity.

A domain whose
maxmem is 128mb would have 2 chunks and so on.
When the domain is destroyed, its chunk(s) are freed.

Again, I see no reason why an ordinary domain would need more than one

Well I think we agree that we would want to give domains more then a chunk of memory, how the memory is sourced beyond the RMA chunk is up for grabs.

I _could_ see that in the near future the the domheap page allocator only gave out chunk granularity.

I would be interested to see allocator usage statistics from a
fully-running system (especially with stressed virtual IO devices). If
it's a relatively fixed amount of memory then I'm OK with restricting
the page/heap allocators to a fixed number of chunks. How to determine
that number is another story though...

I agree, right now we need a simple method for allocating and destroying domains.
Once we are actually dealing with IO we can see how bad things are.
But we need something to get us to that point.


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