Re: [PATCH] efivarfs: Rate limit statfs() handler

Hi Ard,

I like the new approach, it's much simpler and easier to understand

On Tue, Aug 18, 2026 at 04:11:50PM +0200, Ard Biesheuvel wrote:
> Ravi reports that statfs() may be called by unprivileged users on the
> efivarfs mount point, which may result in a flood of calls to the
> QueryVariableInfo() runtime service. These calls are disproportionately
> costly on x86 systems where the variable store is backed by SMM, as each
> SMM entry requires a rendez-vous of all the CPUs.
> 
> So rate limit the calls to QueryVariableInfo() at twice per second, and

It's already a high-rate in performance sensitive environment. I'd have
gone higher at once per 10 seconds for example. But really, this is
minor, so please consider this:

Reviewed-by: <[email protected]>

Regards,

Anisse