From b8fa70b51aa76737bdb6b493901ef7376977489c Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Fri, 9 Aug 2013 19:51:54 +0530 Subject: [PATCH] xen, pvticketlocks: Add xen_nopvspin parameter to disable xen pv ticketlocks Signed-off-by: Jeremy Fitzhardinge Link: http://lkml.kernel.org/r/1376058122-8248-7-git-send-email-raghavendra.kt@linux.vnet.ibm.com Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Raghavendra K T Acked-by: Ingo Molnar Signed-off-by: H. Peter Anvin --- 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; -- 2.7.4