Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754273AbaDDSrN (ORCPT ); Fri, 4 Apr 2014 14:47:13 -0400 Received: from mail.kernel.org ([198.145.19.201]:57178 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753840AbaDDSrK (ORCPT ); Fri, 4 Apr 2014 14:47:10 -0400 From: konrad@kernel.org To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: Konrad Rzeszutek Wilk , Steven Rostedt , stable@vger.kernel.org, Boris Ostrovsky , David Vrabel Subject: [PATCH] xen/spinlock: Don't enable them unconditionally. Date: Fri, 4 Apr 2014 14:48:04 -0400 Message-Id: <1396637284-6312-1-git-send-email-konrad@kernel.org> X-Mailer: git-send-email 1.7.7.6 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Konrad Rzeszutek Wilk 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 CC: Steven Rostedt CC: stable@vger.kernel.org CC: Boris Ostrovsky CC: David Vrabel Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/spinlock.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 581521c..c570fea 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; } -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/