xentrace: print calculated numbers in calculate_tbuf_size()

(xen-unstable changeset 23092:45dafa422812)

Print number of pages to allocate for per-cpu tracebuffer and metadata
to ease debugging when allocation fails.

Signed-off-by: Olaf Hering <olaf@aepfle.de>

---
 xen/common/trace.c |    2 ++
 1 file changed, 2 insertions(+)

Index: xen-4.1.1-testing/xen/common/trace.c
===================================================================
--- xen-4.1.1-testing.orig/xen/common/trace.c
+++ xen-4.1.1-testing/xen/common/trace.c
@@ -128,6 +128,8 @@ static int calculate_tbuf_size(unsigned
     t_info_words = num_online_cpus() * pages + t_info_first_offset;
     t_info_bytes = t_info_words * sizeof(uint32_t);
     t_info_pages = PFN_UP(t_info_bytes);
+    printk(XENLOG_INFO "xentrace: requesting %u t_info pages for %u trace pages on %u cpus\n",
+               t_info_pages, pages, num_online_cpus());
     return pages;
 }