Thank you for the nice explanation. Looks like there isn't any issue to just enable HugePage in general if ignoring the overcommit senario. On Wed, Nov 1, 2023 at 2:33 PM <smooney@redhat.com> wrote:
Folks,
What are the advantages and disadvantages to enable HugePages on compute nodes? I know that HugePages improve performance of VMs because of TLB lookup etc. But if it does improve in most cases then why people why default not turning on HugePage for deployment? using hugepages means no memory over commit.
On Wed, 2023-11-01 at 10:39 -0400, Satish Patel wrote: that is the main disadvantage the other implications is that the memory cannot be swapped that is the other way that hugepages boost performance finally hugepages make vms numa affiend. some peopel just dont want to deal with numa and the numa afifnity implciatieons for sriov
you can disabel numa affinity for sriov device but we default to requiring it if its a numa vm.
in genreal if you dont need over commit there is no reason not to use hugepages in a relitively recent cloud. we added live migraiton support 3 or 4 years ago before that lack of live migration was anohter reason not to use it.
Just trying to find out what could go wrong if I turn on by default HugePage for all deployment?
nothing really that im aware of. many telco cloud do this and its the norm for any NFV workload in most turning guides.
the main implication as an operator is just that you are opting out of memory overcommit if you dont use that anyway then there really isnt a downside anymore.