xen/spinlock: Don't setup xen spinlock IPI kicker if disabled.
There is no need to setup this kicker IPI if we are never going
to use the paravirtualized ticketlock mechanism.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 71db82c..e1bff87 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -105,6 +105,7 @@
static DEFINE_PER_CPU(struct xen_lock_waiting, lock_waiting);
static cpumask_t waiting_cpus;
+static bool xen_pvspin __initdata = true;
static void xen_lock_spinning(struct arch_spinlock *lock, __ticket_t want)
{
int irq = __this_cpu_read(lock_kicker_irq);
@@ -223,6 +224,9 @@
int irq;
char *name;
+ if (!xen_pvspin)
+ return;
+
WARN(per_cpu(lock_kicker_irq, cpu) >= 0, "spinlock on CPU%d exists on IRQ%d!\n",
cpu, per_cpu(lock_kicker_irq, cpu));
@@ -259,13 +263,15 @@
if (xen_hvm_domain())
return;
+ if (!xen_pvspin)
+ return;
+
unbind_from_irqhandler(per_cpu(lock_kicker_irq, cpu), NULL);
per_cpu(lock_kicker_irq, cpu) = -1;
kfree(per_cpu(irq_name, cpu));
per_cpu(irq_name, cpu) = NULL;
}
-static bool xen_pvspin __initdata = true;
void __init xen_init_spinlocks(void)
{
@@ -305,6 +311,9 @@
if (d_xen == NULL)
return -ENOMEM;
+ if (!xen_pvspin)
+ return 0;
+
d_spin_debug = debugfs_create_dir("spinlocks", d_xen);
debugfs_create_u8("zero_stats", 0644, d_spin_debug, &zero_stats);