Re: [libvirt][PATCH v4 0/3] introduce 'restrictive' mode in numatune
On Tue, Mar 23, 2021 at 10:59:02AM +0800, Luyao Zhong wrote:
Before this patch set, numatune only has three memory modes:
static, interleave and prefered. These memory policies are
ultimately set by mbind() system call.
Memory policy could be 'hard coded' into the kernel, but none of
above policies fit our requirment under this case. mbind() support
default memory policy, but it requires a NULL nodemask. So obviously
setting allowed memory nodes is cgroups' mission under this case.
So we introduce a new option for mode in numatune named 'restrictive'.
<numatune>
<memory mode="restrictive" nodeset="1-4,^3"/>
<memnode cellid="0" mode="restrictive"
nodeset="1"/>
<memnode cellid="2" mode="restrictive"
nodeset="2"/>
</numatune>
'restrictive' is rather a wierd name and doesn't really tell me what
the memory policy is going to be. As far as I can tell from the
patches, it seems this causes us to not set any memory alllocation
policy at all. IOW, we're using some undefined host default policy.
Given this I think we should be calling it either "none" or "default"
Regards,
Daniel
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