Re: [PATCH v6 06/11] x86/virt/tdx: Optimize tdx_pamt_get/put()

[Kiryl Shutsemau <kas@kernel.org>]

On Fri, Jun 05, 2026 at 01:40:25PM +0800, Chao Gao wrote:
> On Thu, Jun 04, 2026 at 05:59:02PM +0100, Kiryl Shutsemau wrote:
> >On Tue, May 26, 2026 at 04:42:24PM +0000, Edgecombe, Rick P wrote:
> >> On Tue, 2026-05-26 at 16:57 +0800, Chao Gao wrote:
> >> > > -	scoped_guard(spinlock, &pamt_lock) {
> >> > 
> >> > This converts the scoped_guard() added by the previous patch to
> >> > explicit lock/unlock and goto. It would reduce code churn if the
> >> > previous patch used that form directly.
> >> 
> >> Yea, it's a good point. I actually debated doing it, but decided not to because
> >> the scoped version is cleaner for the non-optimized version. But for
> >> reviewability, never doing the scoped version is probably better.
> >
> >I don't see a reason why we can't keep the scoped_guard() on get side.
> 
> One additional reason to drop scoped_guard() is that it mixes cleanup helpers
> with goto, which is discouraged. See [*]
> 
>  :Lastly, given that the benefit of cleanup helpers is removal of “goto”, and
>  :that the “goto” statement can jump between scopes, the expectation is that
>  :usage of “goto” and cleanup helpers is never mixed in the same function.

Fair enough.

But it can also be address if we free the PAMT page array with the guard
too :P

-- 
  Kiryl Shutsemau / Kirill A. Shutemov