On 10/2/07, Pavel Emelyanov <xemul@openvz.org> wrote:
>
> Such a lookup would require a hastable or something similar. We already
> have such a bad experience (with OpenVZ RSS fractions accounting for
> example). Hash lookups imply the CPU caches screwup and hurt the performance.
> See also the comment below.

I think you could do it with an array lookup if you assigned an index
to each cache as it was created, and used that as an offset into a
per-cgroup array.

>
> I thought the same some time ago and tried to make a per-beancounter kmem
> caches. The result was awful - the memory waste was much larger than in the
> case of pointer-per-object approach.

OK, fair enough.

Was this with a large number of bean counters? I imagine that with a
small number, the waste might be rather more reasonable.

Paul