Re: [x86, paravirt] fd6f48529f: aim7.jobs-per-min -26.1% regression

[Peter Zijlstra <peterz@infradead.org>]

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On Thu, Dec 01, 2016 at 02:07:29AM +0800, kernel test robot wrote:
> 
> Greeting,
> 
> FYI, we noticed a -26.1% regression of aim7.jobs-per-min due to commit:
> 
> 
> commit: fd6f48529f4067c6bfbead88d3d7d117d51150f6 ("x86,paravirt: Optimize native pv_lock_ops.vcpu_is_preempted")
> https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git locking/core
> 

> 
> 8ba24710fb279053  fd6f48529f4067c6bfbead88d3  

So that really is against its parent..

Does something like so fix it?

--- a/arch/x86/kernel/paravirt_patch_32.c
+++ b/arch/x86/kernel/paravirt_patch_32.c
@@ -56,15 +56,19 @@ unsigned native_patch(u8 type, u16 clobb
 				end   = end_pv_lock_ops_queued_spin_unlock;
 				goto patch_site;
 			}
+			goto patch_default;
+
 		case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):
 			if (pv_is_native_vcpu_is_preempted()) {
 				start = start_pv_lock_ops_vcpu_is_preempted;
 				end   = end_pv_lock_ops_vcpu_is_preempted;
 				goto patch_site;
 			}
+			goto patch_default;
 #endif
 
 	default:
+patch_default:
 		ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
 		break;
 
--- a/arch/x86/kernel/paravirt_patch_64.c
+++ b/arch/x86/kernel/paravirt_patch_64.c
@@ -68,15 +68,19 @@ unsigned native_patch(u8 type, u16 clobb
 				end   = end_pv_lock_ops_queued_spin_unlock;
 				goto patch_site;
 			}
+			goto patch_default;
+
 		case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):
 			if (pv_is_native_vcpu_is_preempted()) {
 				start = start_pv_lock_ops_vcpu_is_preempted;
 				end   = end_pv_lock_ops_vcpu_is_preempted;
 				goto patch_site;
 			}
+			goto patch_default;
 #endif
 
 	default:
+patch_default:
 		ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
 		break;