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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2014-04-04 20:48:04 +0200
committerDavid Vrabel <david.vrabel@citrix.com>2014-04-15 18:41:28 +0200
commite0fc17a936334c08b2729fff87168c03fdecf5b6 (patch)
tree8a42f8c774ddd37f5b74650b114a0cade7fd1cd9 /arch/x86
parentxen-pciback: silence an unwanted debug printk (diff)
downloadlinux-e0fc17a936334c08b2729fff87168c03fdecf5b6.tar.xz
linux-e0fc17a936334c08b2729fff87168c03fdecf5b6.zip
xen/spinlock: Don't enable them unconditionally.
The git commit a945928ea2709bc0e8e8165d33aed855a0110279 ('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 <waiman.long@hp.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> CC: stable@vger.kernel.org CC: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/xen/spinlock.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 4d3acc34a998..0ba5f3b967f0 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(&paravirt_ticketlocks_enabled);
return 0;
}