From mboxrd@z Thu Jan 1 00:00:00 1970 From: Raghavendra K T Subject: [PATCH RFC V11 6/18] xen/pvticketlocks: Add xen_nopvspin parameter to disable xen pv ticketlocks Date: Mon, 22 Jul 2013 11:47:59 +0530 Message-ID: <20130722061759.24737.84656.sendpatchset@codeblue> References: <20130722061631.24737.75508.sendpatchset@codeblue> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130722061631.24737.75508.sendpatchset@codeblue> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: gleb@redhat.com, mingo@redhat.com, jeremy@goop.org, x86@kernel.org, konrad.wilk@oracle.com, hpa@zytor.com, pbonzini@redhat.com Cc: gregkh@suse.de, kvm@vger.kernel.org, linux-doc@vger.kernel.org, peterz@infradead.org, drjones@redhat.com, virtualization@lists.linux-foundation.org, andi@firstfloor.org, xen-devel@lists.xensource.com, Raghavendra K T , habanero@linux.vnet.ibm.com, riel@redhat.com, stefano.stabellini@eu.citrix.com, ouyang@cs.pitt.edu, avi.kivity@gmail.com, tglx@linutronix.de, chegu_vinod@hp.com, linux-kernel@vger.kernel.org, srivatsa.vaddagiri@gmail.com, attilio.rao@citrix.com, torvalds@linux-foundation.org List-Id: xen-devel@lists.xenproject.org xen/pvticketlocks: Add xen_nopvspin parameter to disable xen pv ticketlocks From: Jeremy Fitzhardinge Signed-off-by: Jeremy Fitzhardinge Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Raghavendra K T --- 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 31949da..ec9183b 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;