On 7/22/20 9:44 AM, Daniel P. Berrangé wrote: > OpenStack uses TCG in alot of their CI infrastructure for example > and runs multiple VMs. If there's 4 VMs, that's another 4 GB of > RAM usage just silently added on top of the explicit -m value. > > I wouldn't be surprised if this pushes CI into OOM, even without > containers or cgroups being involved, as they have plenty of other > services consuming RAM in the CI VMs.
I would hope that CI would also supply a -tb_size to go along with that -m value. Because we really can't guess on their behalf. > The commit 600e17b261555c56a048781b8dd5ba3985650013 talks about this > minimizing codegen cache flushes, but doesn't mention the real world > performance impact of eliminating those flushes ? Somewhere on the mailing list was this info. It was so dreadfully slow it was *really* noticable. Timeouts everywhere. > > Presumably this makes the guest OS boot faster, but what's the before > and after time ? And what's the time like for values in between the > original 32mb and the new 1 GB ? But it wasn't "the original 32MB". It was the original "ram_size / 4", until that broke due to argument parsing ordering. I don't know what CI usually uses, but I usually use at least -m 4G, sometimes more. What's the libvirt default? r~
