From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v6] kvm: make vcpu life cycle separated from kvm instance Date: Wed, 28 Dec 2011 11:53:09 +0200 Message-ID: <4EFAE705.6070202@redhat.com> References: <1324091975-20930-1-git-send-email-kernelfans@gmail.com> <1324975139-8836-1-git-send-email-kernelfans@gmail.com> <4EF9AA59.7050003@oss.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Takuya Yoshikawa , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, aliguori@us.ibm.com, gleb@redhat.com, mtosatti@redhat.com, xiaoguangrong.eric@gmail.com, jan.kiszka@web.de, Takuya Yoshikawa To: Liu ping fan Return-path: Received: from mx1.redhat.com ([209.132.183.28]:65186 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752150Ab1L1JxV (ORCPT ); Wed, 28 Dec 2011 04:53:21 -0500 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 12/28/2011 08:54 AM, Liu ping fan wrote: > >> > >> struct kvm_vcpu { > >> struct kvm *kvm; > >> + struct list_head list; > >> #ifdef CONFIG_PREEMPT_NOTIFIERS > >> struct preempt_notifier preempt_notifier; > >> #endif > >> @@ -251,12 +252,14 @@ struct kvm { > >> struct mm_struct *mm; /* userspace tied to this vm */ > >> struct kvm_memslots *memslots; > >> struct srcu_struct srcu; > >> + struct srcu_struct srcu_vcpus; > >> + > > > > Another srcu. This alone is worth explaining in the changelog IMO. > > > Sorry, but why? I think it is just a srcu, and because it has > different aim and want a independent grace period, so not multiplex > kvm->srcu. There is Documentation/virtual/kvm/locking.txt for that. btw, why does it have to be srcu? Is rcu insufficient? Why do we want an independent grace period, is hotunplugging a vcpu that much different from hotunplugging memory? -- error compiling committee.c: too many arguments to function