xen/trace: add multicall tracing

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

1 files changed, 23 insertions, 8 deletions

diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c
index b9bf19884bc5..7074c7ebfff2 100644
--- a/arch/x86/xen/multicalls.c
+++ b/arch/x86/xen/multicalls.c
@@ -65,6 +65,8 @@ void xen_mc_flush(void)
            something in the middle */
         local_irq_save(flags);
 
+        trace_xen_mc_flush(b->mcidx, b->argidx, b->cbidx);
+
         if (b->mcidx) {
 #if MC_DEBUG
                 memcpy(b->debug, b->entries,
@@ -116,11 +118,15 @@ struct multicall_space __xen_mc_entry(size_t args)
         struct multicall_space ret;
         unsigned argidx = roundup(b->argidx, sizeof(u64));
 
+        trace_xen_mc_entry_alloc(args);
+
         BUG_ON(preemptible());
         BUG_ON(b->argidx >= MC_ARGS);
 
         if (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();
                 argidx = roundup(b->argidx, sizeof(u64));
         }
@@ -145,20 +151,25 @@ struct multicall_space xen_mc_extend_args(unsigned long op, size_t size)
         BUG_ON(preemptible());
         BUG_ON(b->argidx >= MC_ARGS);
 
-        if (b->mcidx == 0)
-                return ret;
-
-        if (b->entries[b->mcidx - 1].op != op)
-                return ret;
+        if (unlikely(b->mcidx == 0 ||
+                     b->entries[b->mcidx - 1].op != op)) {
+                trace_xen_mc_extend_args(op, size, XEN_MC_XE_BAD_OP);
+                goto out;
+        }
 
-        if ((b->argidx + size) >= MC_ARGS)
-                return ret;
+        if (unlikely((b->argidx + size) >= MC_ARGS)) {
+                trace_xen_mc_extend_args(op, size, XEN_MC_XE_NO_SPACE);
+                goto out;
+        }
 
         ret.mc = &b->entries[b->mcidx - 1];
         ret.args = &b->args[b->argidx];
         b->argidx += size;
 
         BUG_ON(b->argidx >= MC_ARGS);
+
+        trace_xen_mc_extend_args(op, size, XEN_MC_XE_OK);
+out:
         return ret;
 }
 
@@ -167,8 +178,12 @@ void xen_mc_callback(void (*fn)(void *), void *data)
         struct mc_buffer *b = &__get_cpu_var(mc_buffer);
         struct callback *cb;
 
-        if (b->cbidx == MC_BATCH)
+        if (b->cbidx == MC_BATCH) {
+                trace_xen_mc_flush_reason(XEN_MC_FL_CALLBACK);
                 xen_mc_flush();
+        }
+
+        trace_xen_mc_callback(fn, data);
 
         cb = &b->callbacks[b->cbidx++];
         cb->fn = fn;