This patch adds a XEN init function to activate the unfair queue spinlock in a XEN guest when the PARAVIRT_UNFAIR_LOCKS kernel config option is selected.
Signed-off-by: Waiman Long <[email protected]> --- arch/x86/xen/setup.c | 19 +++++++++++++++++++ 1 files changed, 19 insertions(+), 0 deletions(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 0982233..66bb6f5 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -625,3 +625,22 @@ void __init xen_arch_setup(void) numa_off = 1; #endif } + +#ifdef CONFIG_PARAVIRT_UNFAIR_LOCKS +/* + * Enable unfair lock if running in a Xen guest + */ +static __init int xen_unfair_locks_init_jump(void) +{ + /* + * Disable unfair lock if not running in a PV domain + */ + if (!xen_pv_domain()) + return 0; + + static_key_slow_inc(¶virt_unfairlocks_enabled); + + return 0; +} +early_initcall(xen_unfair_locks_init_jump); +#endif -- 1.7.1 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
