Re: [PATCH 0/3][RFC] NUMA: add host side pinning

[Avi Kivity <avi@redhat.com>]

On 06/24/2010 01:58 PM, Andre Przywara wrote:
>> So who would create the /dev/shm/nodeXX files?
>
> Currently it is QEMU. It creates a somewhat unique filename, opens and 
> unlinks it. The difference would be to name the file after the option 
> and to not unlink it.
>
> > I can imagine starting numactl before qemu, even though that's
> > cumbersome. I don't think it's feasible to start numactl after
> > qemu is running. That'd involve way too much magic that I'd prefer
> > qemu to call numactl itself.
> Using the current code the files would not exist before QEMU allocated 
> RAM, and after that it could already touch pages before numactl set 
> the policy.

Non-anonymous memory doesn't work well with ksm and transparent 
hugepages.  Is it possible to use anonymous memory rather than file backed?

> To avoid this I'd like to see the pinning done from within QEMU. I am 
> not sure whether calling numactl via system() and friends is OK, I'd 
> prefer to run the syscalls directly (like in patch 3/3) and pull the 
> necessary options into the -numa pin,... command line. We could mimic 
> numactl's syntax here.

Definitely not use system(), but IIRC numactl has a library interface?


-- 
error compiling committee.c: too many arguments to function