On 03/19/2014 04:28 PM, Konrad Rzeszutek Wilk wrote:
On Wed, Mar 19, 2014 at 04:14:05PM -0400, Waiman Long wrote: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<Waiman.Long@xxxxxx> --- 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;I would just make this 'xen_domain'. Not sure why you need to have it only for PV while the PVHVM guests can also use it?
The compilation of the setup.c file should have implied xen_domain already (at least HVM). The check is added to make sure that unfair lock won't be enabled on bare metal. As for PVHVM, is there a way to detect it is running as such which is distinct from HVM?
Would it also make sense to use the same printk statement that the KVM has?
Yes, I can add a printk statement like KVM. -Longman _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
