| Message ID | 1402418250-6806-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 0e36cde..37c6970 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; }
This is a note to let you know that I have just added a patch titled xen/spinlock: Don't enable them unconditionally. to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11.3. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 659c181427a26a95fc592dd3187941e52af6d9dc Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Date: Fri, 4 Apr 2014 14:48:04 -0400 Subject: xen/spinlock: Don't enable them unconditionally. commit e0fc17a936334c08b2729fff87168c03fdecf5b6 upstream. 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: 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> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/x86/xen/spinlock.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) -- 1.9.1