From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] KVM: Start lock documentation Date: Tue, 15 Feb 2011 19:07:12 +0200 Message-ID: <4D5AB2C0.3050202@redhat.com> References: <4D52A090.5010308@siemens.com> <20110215164414.GA12410@amt.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Jan Kiszka , kvm To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:32914 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755662Ab1BORG4 (ORCPT ); Tue, 15 Feb 2011 12:06:56 -0500 In-Reply-To: <20110215164414.GA12410@amt.cnet> Sender: kvm-owner@vger.kernel.org List-ID: On 02/15/2011 06:44 PM, Marcelo Tosatti wrote: > On Wed, Feb 09, 2011 at 03:11:28PM +0100, Jan Kiszka wrote: >> The goal of this document shall be >> - overview of all locks used in KVM core >> - provide details on the scope of each lock >> - explain the lock type, specifically of a raw spin locks >> - provide a lock ordering guide >> >> Start with one dependency chain and two locks. >> >> Signed-off-by: Jan Kiszka >> --- >> Documentation/kvm/locking.txt | 30 ++++++++++++++++++++++++++++++ >> 1 files changed, 30 insertions(+), 0 deletions(-) >> create mode 100644 Documentation/kvm/locking.txt >> >> diff --git a/Documentation/kvm/locking.txt b/Documentation/kvm/locking.txt >> new file mode 100644 >> index 0000000..23f9092 >> --- /dev/null >> +++ b/Documentation/kvm/locking.txt >> @@ -0,0 +1,30 @@ >> +KVM Lock Overview >> +================= >> + >> +1. Acquisition Orders >> +--------------------- >> + >> +kvm_lock >> ++-> kvm::srcu / kvm::lock >> + +-> kvm::slots_lock >> + +-> kvm::mmu_lock >> +... > Its not easy to understand what you mean here. What kvm_lock has to do > with the ordering described below it? > Yeah, I meant to make the same comment but forgot. I suggest a union of paths: kvm::srcu (read) -> { fields } | kvm::slots_lock(write) -> { fields } but let's start with the reference section.