Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751609Ab3IPWMF (ORCPT ); Mon, 16 Sep 2013 18:12:05 -0400 Received: from mail1.windriver.com ([147.11.146.13]:65409 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751043Ab3IPWMC (ORCPT ); Mon, 16 Sep 2013 18:12:02 -0400 Message-ID: <5237824E.5090802@windriver.com> Date: Mon, 16 Sep 2013 18:12:30 -0400 From: Paul Gortmaker User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: Paolo Bonzini CC: , , , Subject: Re: [PATCH 0/3] KVM: Make kvm_lock non-raw References: <1379340373-5135-1-git-send-email-pbonzini@redhat.com> In-Reply-To: <1379340373-5135-1-git-send-email-pbonzini@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [128.224.146.65] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1640 Lines: 43 On 13-09-16 10:06 AM, Paolo Bonzini wrote: > Paul Gortmaker reported a BUG on preempt-rt kernels, due to taking the > mmu_lock within the raw kvm_lock in mmu_shrink_scan. He provided a > patch that shrunk the kvm_lock critical section so that the mmu_lock > critical section does not nest with it, but in the end there is no reason > for the vm_list to be protected by a raw spinlock. Only manipulations > of kvm_usage_count and the consequent hardware_enable/disable operations > are not preemptable. > > This small series thus splits the kvm_lock in the "raw" part and the > "non-raw" part. > > Paul, could you please provide your Tested-by? Sure, I'll go back and see if I can find what triggered it in the original report, and give the patches a spin on 3.4.x-rt (and probably 3.10.x-rt, since that is where rt-current is presently). Paul. -- > > Thanks, > > Paolo > > Paolo Bonzini (3): > KVM: cleanup (physical) CPU hotplug > KVM: protect kvm_usage_count with its own spinlock > KVM: Convert kvm_lock back to non-raw spinlock > > Documentation/virtual/kvm/locking.txt | 8 ++++-- > arch/x86/kvm/mmu.c | 4 +-- > arch/x86/kvm/x86.c | 8 +++--- > include/linux/kvm_host.h | 2 +- > virt/kvm/kvm_main.c | 51 ++++++++++++++++++----------------- > 5 files changed, 40 insertions(+), 33 deletions(-) > -- 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/