On Wed, Jul 25, 2018 at 03:43:59PM +0200, Andrew Jones wrote: > On Wed, Jul 25, 2018 at 12:41:06PM +0100, Dave Martin wrote: [...] > > The main purpose of system_supports_sve() here is to shadow the check on > > vcpu_arch->flags with a static branch. If the system doesn't support > > SVE, we don't pay the runtime cost of the dynamic check on > > vcpu_arch->flags. > > > > If the kernel is built with CONFIG_ARM64_SVE=n, the dynamic check should > > be entirely optimised away by the compiler. > > Ah, that makes sense. Thanks for clarifying it. > > > > > I'd rather not add an explicit comment for this because the same > > convention is followed elsewhere -- thus for consistency the comment > > would need to be added in a lot of places. > > Agreed that we don't need a comment. A note in the commit message might > have been nice though. Sure, I'll add something in the respin. Cheers ---Dave _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
