xen/multicalls: add unlikely around slowpath in __xen_mc_entry()

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c
index 3001162c4bce1495a10c3d17806b67e871c02536..cc71f7cf1adc0ae4748281f64cf2ccbc2f6e8043 100644 (file)
--- a/arch/x86/xen/multicalls.c
+++ b/arch/x86/xen/multicalls.c
@@ -123,8 +123,8 @@ struct multicall_space __xen_mc_entry(size_t args)
        BUG_ON(preemptible());
        BUG_ON(b->argidx >= MC_ARGS);
 
-       if (b->mcidx == MC_BATCH ||
-           (argidx + args) >= MC_ARGS) {
+       if (unlikely(b->mcidx == MC_BATCH ||
+                    (argidx + args) >= MC_ARGS)) {
                trace_xen_mc_flush_reason((b->mcidx == MC_BATCH) ?
                                          XEN_MC_FL_BATCH : XEN_MC_FL_ARGS);
                xen_mc_flush();