[libvirt] [PATCH 4/5] qemu: Build command line for NUMA tuning

[Osier Yang]

于 2011年05月06日 17:23, Daniel P. Berrange 写道:
> On Thu, May 05, 2011 at 04:30:30PM -0400, Bill Gray wrote:
>>
>> Hi Daniel,
>>
>> How can we get NUMA-aligned memory and CPUs if we apply binding APIs
>> after the process has already started?   Might not all the memory
>> already be allocated on the wrong nodes by then?
>
> The policy has to be set after fork'ing the new QEMU process, but
> before exec'ing QEMU. This is essentially what you're doing with
> numactl, but with the problem of an extra binary that screws up
> the SELinux domain transitions from libvirtd_t ->  svirt_t.
>
>> For expert users, what are the problems with starting qemu with an
>> external numactl command (with --cpunodebind and --membind) to
>> guarantee optimal alignment?
>
> Adding an intermediate process will prevent the neccessary SELinux
> domain transitions from working. We don't want to allow the
> numactl binary to be able to transition to svirt_t because that
> would be inappropriate for most users of numactl

This make sense, as you said in another mail, perhaps we need to do some
work on __virExec, will make v2 series. Thanks for feedback.

Regards
Osier