On Mon, May 31, 2021 at 10:36:01AM +0200, Michal Privoznik wrote:
We allow configuring HMAT for domains since v6.6.0-rc1~249 (and
friends). Basically, HMAT is more fine grained description of
interconnects of NUMA nodes than basic NUMA distances. The former
describes bandwidths and latencies while the latter is some
dimensionless and normalized number.
Anyway, mgmt apps did not really know what values to set for HMAT
because we are not exposing them in capabilities because we were waiting
on kernel to expose them. And it just did.
In 09/10 I'm describing sysfs interface briefly and also mention that
there's no interpretation of links to memory side caches, yet. I'm
talking to kernel developers so we might get some movement there. But
also, I'm not sure whether it's worth the effort OR if there really is a
machine that has separate links to main memory and caches.
Here's link to ACPI spec:
https://uefi.org/sites/default/files/resources/ACPI_6_2.pdf
Look for "5.2.27.4 System Locality Latency and Bandwidth Information
Structure".
And here's link to sysfs docs:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/D...
Michal Prívozník (10):
tests: glib-ify vircaps2xmltest
schemas: Allow zero <cpu/> for capabilities
capabilities: Separate <cpu/> formatting into a function
numa_conf: Rename virDomainCache* to virNumaCache*
numa_conf: Expose virNumaCache formatter
capabilities: Expose NUMA memory side cache
numa_conf: Rename virDomainNumaInterconnect* to virNumaInterconnect*
numa_conf: Expose virNumaInterconnect formatter
To these 8 patches above:
Reviewed-by: Martin Kletzander <mkletzan(a)redhat.com>
capabilities: Expose NUMA interconnects
vircaps2xmltest: Introduce HMAT test case
These last two need some fix and/or explanation.