Re: [PATCH] kvm: x86: Print "disabled by bios" only once per host

From: Jim Mattson
Date: Fri Feb 14 2020 - 12:43:31 EST


On Fri, Feb 14, 2020 at 6:33 AM Erwan Velu <erwanaliasr1@xxxxxxxxx> wrote:
>
> The current behavior is to print a "disabled by bios" message per CPU thread.
> As modern CPUs can have up to 64 cores, 128 on a dual socket, and turns this
> printk to be a pretty noisy by showing up to 256 times the same line in a row.
>
> This patch offer to only print the message once per host considering the BIOS will
> disabled the feature for all sockets/cores at once and not on a per core basis.

That's quite an assumption you're making. I guess I've seen more
broken BIOSes than you have. :-) Still, I would rather see the message
just once--perhaps with an additional warning if all logical
processors aren't in agreement.