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