Libguestfs - May 2016 - [PATCH] launch: Use tsc=reliable.

I've pushed this change already actually.

No one seems to know if this option is safe.  If you see strange
timing-related things happening in libguestfs, let us know!

Rich.

This saves about 21ms per secondary CPU when using guestfs_set_smp.
---
 src/launch.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/launch.c b/src/launch.c
index cc0f8d7..72a8b29 100644
--- a/src/launch.c
+++ b/src/launch.c
@@ -372,6 +372,8 @@ guestfs_int_appliance_command_line (guestfs_h *g, const char
*appliance_dev,
      " cgroup_disable=memory"   /* saves us about 5 MB of RAM */
      " usbcore.nousb"           /* disable USB, only saves about 1ms
*/
      " cryptomgr.notests"       /* disable crypto tests, saves 28ms
*/
+     " tsc=reliable"            /* don't synch TSCs when using
SMP,
+                                   saves 21ms for each secondary vCPU */
      " 8250.nr_uarts=1"         /* don't scan all 8250 UARTS */
      "%s"                       /* root=appliance_dev */
      " %s"                      /* selinux */
-- 
2.7.4