From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gregory Haskins" Subject: Re: [PATCH] interrupt preemption support Date: Mon, 19 Mar 2007 10:09:33 -0400 Message-ID: <45FE5346.BA47.005A.0@novell.com> References: <45F97019.BA47.005A.0@novell.com> <45FA414C.1040703@qumranet.com> <45FA4489.BA47.005A.0@novell.com> <45FCD226.2010603@qumranet.com> <45FE4FB1.BA47.005A.0@novell.com> <45FE9793.3060204@qumranet.com> <45FE9827.5030200@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: "Avi Kivity" Return-path: In-Reply-To: <45FE9827.5030200-atKUWr5tajBWk0Htik3J/w@public.gmane.org> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org >>> On Mon, Mar 19, 2007 at 10:03 AM, in message <45FE9827.5030200-atKUWr5tajBWk0Htik3J/w@public.gmane.org>, Avi Kivity wrote: > Avi Kivity wrote: >> Gregory Haskins wrote: >>> Hi Avi, >>> You make good points. I will convert to a nest lock design and >>> resubmit. Should I use two mutexes, or a mutex and spinlock? >>> >>> Also, do you have any suggestions on the signum I should use to IPI >>> the running guest? Should I use one of the normal signals (SIGUSR) >>> or should I start a block of defined signals in the RT range (>32)? >>> >> >> For a short term solution, where the apic is in userspace, we can just >> say ipi == signal, and not require any locking. Qemu will catch the >> signal and call the appropriate apic function. The signal number >> should be set from userspace. >> > > Note that as long as the apic code is in userspace, the sending side is > also in userspace, so all the IPI related stuff doesn't touch the kernel. I see. So really the entire approach I took (against the kernel code) is wrong, and I should focus on the QEMU side? -Greg ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV