xen/pvticketlocks: Add xen_nopvspin parameter to disable xen pv ticketlocks
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/xen/spinlock.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index a458729..669a971 100644
--- 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;
--
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