xen, pvticketlocks: Add xen_nopvspin parameter to disable xen pv tick…

…etlocks Signed-off-by: Jeremy Fitzhardinge <[email protected]> Link: http://lkml.kernel.org/r/1376058122-8248-7-git-send-email-raghavendra.kt@linux.vnet.ibm.com Reviewed-by: Konrad Rzeszutek Wilk <[email protected]> Signed-off-by: Raghavendra K T <[email protected]> Acked-by: Ingo Molnar <[email protected]> Signed-off-by: H. Peter Anvin <[email protected]>
kyagi · Aug 9, 2013 · b8fa70b · b8fa70b
1 parent 80bd58f
commit b8fa70b
Showing 1 changed file with 14 additions and 0 deletions.
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
@@ -244,6 +244,8 @@ void xen_uninit_lock_cpu(int cpu)
 	per_cpu(irq_name, cpu) = NULL;
 }
 
+static bool xen_pvspin __initdata = true;
+
 void __init xen_init_spinlocks(void)
 {
 	/*
@@ -253,10 +255,22 @@ void __init xen_init_spinlocks(void)
 	if (xen_hvm_domain())
 		return;
 
+	if (!xen_pvspin) {
+		printk(KERN_DEBUG "xen: PV spinlocks disabled\n");
+		return;
+	}
+
 	pv_lock_ops.lock_spinning = xen_lock_spinning;
 	pv_lock_ops.unlock_kick = xen_unlock_kick;
 }
 
+static __init int xen_parse_nopvspin(char *arg)
+{
+	xen_pvspin = false;
+	return 0;
+}
+early_param("xen_nopvspin", xen_parse_nopvspin);
+
 #ifdef CONFIG_XEN_DEBUG_FS
 
 static struct dentry *d_spin_debug;