On 2025-09-05 15:30:36 [+0200], Ard Biesheuvel wrote:

From: Ard Biesheuvel <ardb@kernel.org>

…

Note that this is only a partial solution in terms of RT guarantees,
given that the runtime services execute at the same privilege level as
the kernel, and can therefore disable interrupts (and therefore
preemption) directly. But it should prevent scheduling latency spikes
for EFI calls that simply take a long time to run to completion.

That sounds nice. There is no feature flag that could tell if a specific
EFI-call (or any) will disable interrupts, right? But if the source code
is available, you could check.

Sebastian