x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted()

[linux.git] / arch / x86 / kernel / paravirt_patch_32.c

diff --git a/arch/x86/kernel/paravirt_patch_32.c b/arch/x86/kernel/paravirt_patch_32.c
index 920c6ae085923c5adda13d72593a4d566376035b..ff03dbd286251b254f9cf1d0d063ddc0489e8c4a 100644 (file)
--- a/arch/x86/kernel/paravirt_patch_32.c
+++ b/arch/x86/kernel/paravirt_patch_32.c
@@ -12,6 +12,7 @@ DEF_NATIVE(pv_cpu_ops, clts, "clts");
 
 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
 DEF_NATIVE(pv_lock_ops, queued_spin_unlock, "movb $0, (%eax)");
+DEF_NATIVE(pv_lock_ops, vcpu_is_preempted, "xor %eax, %eax");
 #endif
 
 unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len)
@@ -27,6 +28,7 @@ unsigned paravirt_patch_ident_64(void *insnbuf, unsigned len)
 }
 
 extern bool pv_is_native_spin_unlock(void);
+extern bool pv_is_native_vcpu_is_preempted(void);
 
 unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
                      unsigned long addr, unsigned len)
@@ -56,6 +58,12 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
                                end   = end_pv_lock_ops_queued_spin_unlock;
                                goto patch_site;
                        }
+               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;
+                       }
 #endif
 
        default: