xen: add debugfs support

Add support for exporting statistics on mmu updates, multicall
batching and pv spinlocks into debugfs. The base path is xen/ and
each subsystem adds its own directory: mmu, multicalls, spinlocks.

In each directory, writing 1 to "zero_stats" will cause the
corresponding stats to be zeroed the next time they're updated.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 1 deletions

diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index 3815e425f470..d3e68465ace9 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -27,4 +27,12 @@ config XEN_MAX_DOMAIN_MEMORY
 config XEN_SAVE_RESTORE
        bool
        depends on PM
-       default y
\ No newline at end of file
+       default y
+
+config XEN_DEBUG_FS
+        bool "Enable Xen debug and tuning parameters in debugfs"
+        depends on XEN && DEBUG_FS
+        default n
+        help
+          Enable statistics output and various tuning options in debugfs.
+          Enabling this option may incur a significant performance overhead.
\ No newline at end of file