Messages in this thread | | | Date | Wed, 9 Jun 2004 17:56:13 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH] Use numa policy API for boot time policy |
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On Thu, 10 Jun 2004 01:44:29 +1000 Anton Blanchard <anton@samba.org> wrote:
> > > It would be a one liner change to allow process policy interleaving > > for orders > 0 in mempolicy. But I'm not sure how useful it is, since > > the granuality would be really bad. > > OK. Id like to take a quick look at order > 0 allocations during boot > to see if its worth it. The ppc64 page size is small and we might be > doing a significant number of order 1 allocations.
For what?
> > Have you ever tried to switch to implement a vmalloc_interleave() for these > > tables instead? My bet is that it will perform better. > > Im warming to this idea. We would need a per arch override, since there > is a trade off here between interleaving and TLB usage.
Actually just standard vmalloc is enough. The interleave policy in alloc_pages will transparently interleave the order 0 pages allocated by vmalloc.
When I find some time I will try that on Opteron too.
> > We also have a problem in 2.6 on our bigger machines where our dcache > hash and inode hash cache are limited to MAX_ORDER (16MB on ppc64). By > using vmalloc would allow us to interleave the memory and allocate more > than 16MB for those hashes.
IMHO 16MB hash table for a kernel structure is madness. A different data structure is probably needed if it's really a problem (is your dcache that big?). Or maybe just limit the dcache more aggressively to keep the max number of entries smaller.
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