[Xen-devel] Question about memory allocation on NUMA node.

Yuji Shimada
Fri, 17 Oct 2008 10:28:29 -0000

I have a question about memory allocation on NUMA node for Xen
Hypervisor.

I think that the memory relating guest domain should be allocated from
the NUMA node on which the guest run.
Because the latency of the same NUMA node is better than that of a
different one.

According to this idea, most of the codes are good in xen-unstable.
But some memory relating guest domain are allocated from the NUMA node
on which CPU #0 run.

For example,
    - xen/arch/x86/domain.c
        setup_compat_l4(struct vcpu *v)
          struct page_info *pg = alloc_domheap_page(NULL, 0);

I think this memory should be allocated from the NUMA node on which the
guest run.

For example,
    - xen/arch/x86/domain.c at
        setup_compat_l4(struct vcpu *v)
          struct page_info *pg = alloc_domheap_page(NULL,
                                 MEMF_node(domain_to_node(v->domain)));

As a result, machine performance becomes better.

What do you think about this idea?
I''d like some comments.

If the developers agree with me, I would like to list them and submit
patch.

Thanks,

--
Yuji Shimada