From mboxrd@z Thu Jan 1 00:00:00 1970 From: Raghavendra K T Subject: Re: [PATCH 9/9] qspinlock, x86, kvm: Implement KVM support for paravirt qspinlock Date: Fri, 20 Mar 2015 13:13:56 +0530 Message-ID: <550BCFBC.9000106@linux.vnet.ibm.com> References: <20150316131613.720617163@infradead.org> <20150316133112.333845162@infradead.org> <550A3863.2060808@hp.com> <20150319100121.GL21418@twins.programming.kicks-ass.net> <550B3ACF.4050908@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <550B3ACF.4050908@hp.com> 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: Waiman Long Cc: linux-arch@vger.kernel.org, riel@redhat.com, kvm@vger.kernel.org, konrad.wilk@oracle.com, Peter Zijlstra , scott.norton@hp.com, x86@kernel.org, paolo.bonzini@gmail.com, oleg@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com, david.vrabel@citrix.com, hpa@zytor.com, luto@amacapital.net, xen-devel@lists.xenproject.org, tglx@linutronix.de, paulmck@linux.vnet.ibm.com, torvalds@linux-foundation.org, boris.ostrovsky@oracle.com, virtualization@lists.linux-foundation.org, doug.hatch@hp.com List-Id: virtualization@lists.linuxfoundation.org On 03/20/2015 02:38 AM, Waiman Long wrote: > On 03/19/2015 06:01 AM, Peter Zijlstra wrote: [...] > You are probably right. The initial apply_paravirt() was done before the > SMP boot. Subsequent ones were at kernel module load time. I put a > counter in the __native_queue_spin_unlock() and it registered 26949 > unlock calls in a 16-cpu guest before it got patched out. because even printks take lock..