Re: [RFC PATCH 1/3] x86/mm: fix LAM cr3 mask inconsistency during context switch

From: Yosry Ahmed
Date: Thu Mar 07 2024 - 18:22:13 EST


> > The "set_" naming bugs me in both of the sites that get modified here.
> > I'd be with a new name that fits better, if we can think of one.
>
> Is it because it's not clear we are updating cpu_tlbstate (in which case
> I think update_cpu_tlbstate_lam() is an improvement), or is it because
> the function returns a value now? If the latter we can put "return" in
> the name somewhere, or keep the function void and pass in an output
> parameter.

Or we can avoid returning a value from the helper and avoid passing an
mm. The callers would be more verbose, they'll have to call
mm_lam_cr3_mask() and mm_untag_mask() and pass the results into the
helper (set_tlbstate_lam_mode() or update_cpu_tlbstate_lam()). Another
advantage of this is that we can move the READ_ONCE to
switch_mm_irqs_off() and keep the comment here.

WDYT?