Re: [PATCH v3 00/12] KVM: selftests: Add more syscall wrappers, fix hardware_disable_test

[Sean Christopherson]

On Fri, Jul 31, 2026, Yosry Ahmed wrote:
> On Fri, Jul 31, 2026 at 12:56 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
> >
> > Third time's a charm.  Sorry for the spam.
> >
> > Buried in the middle of this is a fix for the hardware_disable_test where
> > it can end up with a runtime of multiple minutes when running a preemptible
> > kernels on a large NUMA system.  Turns out my analysis/guess in v1 was wrong;
> > the problem isn't direct CPU contention, it's that letting the workers do any
> > amount of "real" work on any CPUs leads to pthread_create() slowdowns from
> > the perspective of the caller.
> 
> How long does the test take to run with this series?

Less than 5 seconds if nothing else is running.  ~12 seconds if I run it
concurrently with mmu_stress_test using default settings, and ~25 seconds if I
run it on an overloaded system (naively running all selftests in parallel).