On Sun, Jul 19, 2026 at 01:40:28PM +0100, Mark Brown wrote: > On Sun, Jul 19, 2026 at 09:35:53AM +0100, Marc Zyngier wrote:
> > So leave this is a straight ISB, no optimisation. Once you come back > > with actual data showing that this is a terrible bottleneck affecting > > real workloads on real HW, we'll look at it. But until then, please > > keep it as stupid as possible. > I've already left the KVM hypervisor code like that - I only updated the > code here in the main kernel since that keeps the end effect for > existing systems and workloads the same. I am aware that there has been > a great deal of attention paid to the barriers we have in the context > switch path so I am concerned that other people might have a different > view on adding one. It does also look odd do a conditional update of SMCR_EL1 and then unconditionally add a barrier after it, even if the conditional update suppressed the write.
signature.asc
Description: PGP signature
