From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH v3 0/6] powerpc use pv-qpsinlock as the default spinlock implemention Date: Thu, 26 May 2016 18:54:23 +0200 Message-ID: <20160526165423.GN3206@twins.programming.kicks-ass.net> References: <1464164289-6124-1-git-send-email-xinhui.pan@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1464164289-6124-1-git-send-email-xinhui.pan@linux.vnet.ibm.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: Pan Xinhui Cc: jeremy@goop.org, mpe@ellerman.id.au, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, chrisw@sous-sol.org, mingo@redhat.com, paulus@samba.org, benh@kernel.crashing.org, akataria@vmware.com, paulmck@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org List-Id: virtualization@lists.linuxfoundation.org On Wed, May 25, 2016 at 04:18:03PM +0800, Pan Xinhui wrote: > I do several tests on pseries IBM,8408-E8E with 32cpus, 64GB memory. > benchmark test results are below. > _____test________________spinlcok______________pv-qspinlcok_____ > | compiling takes| 22m | 22m | How can a kernel build take 22 minutes with 32 CPUs? That's far too long. My 40 CPU IVB-EP takes all of 50 seconds to build an x86_64-defconfig from scratch.