From e1024a817c071dd96db2bd0185e257f51ab1a540 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Fri, 4 Apr 2014 14:48:04 -0400 Subject: [PATCH] xen/spinlock: Don't enable them unconditionally. The git commit 46271cafbbbedd8bb33e26ede4c61418b025ef18 ('xen: Do not enable spinlocks before jump_label_init() has executed') was added to deal with the jump machinery. Earlier the code that turned on the jump label was only called by Xen specific functions. But now that it had been moved to the initcall machinery it gets called on Xen, KVM, and baremetal - ouch!. And the detection machinery to only call it on Xen wasn't remembered in the heat of merge window excitement. This means that the slowpath is enabled on baremetal while it should not be. Reported-by: Waiman Long Acked-by: Steven Rostedt CC: stable@vger.kernel.org CC: Boris Ostrovsky Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: David Vrabel --- arch/x86/xen/spinlock.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 4d3acc34a998e..0ba5f3b967f00 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -274,7 +274,7 @@ void __init xen_init_spinlocks(void) printk(KERN_DEBUG "xen: PV spinlocks disabled\n"); return; } - + printk(KERN_DEBUG "xen: PV spinlocks enabled\n"); pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(xen_lock_spinning); pv_lock_ops.unlock_kick = xen_unlock_kick; } @@ -290,6 +290,9 @@ static __init int xen_init_spinlocks_jump(void) if (!xen_pvspin) return 0; + if (!xen_domain()) + return 0; + static_key_slow_inc(¶virt_ticketlocks_enabled); return 0; } -- 2.39.5