On Mon, 26 Mar 2018, Wanpeng Li wrote:
I didn't see any issue when testing this patch, could you elaborate what's the bulky mechanism and how it conflicts with early smp bootup stages? In addition, do you mean the xen fix is also not suitable?
I have nothing against your patch (or the xen one for that matter), other than the fact that both seem like band-aid solutions to being able to move up the jump label init call. I was actually peddling a similar patch but didn't want to add the extra callback just for that -- at least xen already had smp_ops.smp_prepare_cpus. Instead of dropping the patches in -tip (ie: delaying the feature), I have nothing against these fixes being merged. If a better solution is available later, we can always move dealing with virt_spin_lock_key back into smp_prepare_boot_cpu(). Also a bit unrelated, but am I correct to assume that KVM_HINTS_DEDICATED can be used via qemu? I've only been dealing with kernel parameters. Thanks, Davidlohr
