Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964801AbaDCCKw (ORCPT ); Wed, 2 Apr 2014 22:10:52 -0400 Received: from g6t1524.atlanta.hp.com ([15.193.200.67]:9839 "EHLO g6t1524.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932443AbaDCCKu (ORCPT ); Wed, 2 Apr 2014 22:10:50 -0400 Message-ID: <533CC309.3020607@hp.com> Date: Wed, 02 Apr 2014 22:10:17 -0400 From: Waiman Long User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.12) Gecko/20130109 Thunderbird/10.0.12 MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: Marcos Matsunaga , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Peter Zijlstra , linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, kvm@vger.kernel.org, Paolo Bonzini , "Paul E. McKenney" , Rik van Riel , Linus Torvalds , Raghavendra K T , David Vrabel , Oleg Nesterov , Gleb Natapov , Aswin Chandramouleeswaran , Scott J Norton , Chegu Vinod , boris.ostrovsky@oracle.com Subject: Re: [PATCH v8 00/10] qspinlock: a 4-byte queue spinlock with PV support References: <1396445259-27670-1-git-send-email-Waiman.Long@hp.com> <20140402143201.GF12188@phenom.dumpdata.com> <533C7485.3030203@hp.com> In-Reply-To: <533C7485.3030203@hp.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/02/2014 04:35 PM, Waiman Long wrote: > On 04/02/2014 10:32 AM, Konrad Rzeszutek Wilk wrote: >> On Wed, Apr 02, 2014 at 09:27:29AM -0400, Waiman Long wrote: >>> N.B. Sorry for the duplicate. This patch series were resent as the >>> original one was rejected by the vger.kernel.org list server >>> due to long header. There is no change in content. >>> >>> v7->v8: >>> - Remove one unneeded atomic operation from the slowpath, thus >>> improving performance. >>> - Simplify some of the codes and add more comments. >>> - Test for X86_FEATURE_HYPERVISOR CPU feature bit to enable/disable >>> unfair lock. >>> - Reduce unfair lock slowpath lock stealing frequency depending >>> on its distance from the queue head. >>> - Add performance data for IvyBridge-EX CPU. >> FYI, your v7 patch with 32 VCPUs (on a 32 cpu socket machine) on an >> HVM guest under Xen after a while stops working. The workload >> is doing 'make -j32' on the Linux kernel. >> >> Completely unresponsive. Thoughts? >> > > Thank for reporting that. I haven't done that much testing on Xen. My > focus was in KVM. I will perform more test on Xen to see if I can > reproduce the problem. > BTW, does the halting and sending IPI mechanism work in HVM? I saw that in RHEL7, PV spinlock was explicitly disabled when in HVM mode. However, this piece of code isn't in upstream code. So I wonder if there is problem with that. -Longman -- 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/