From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [PATCH][RFC] kvm-scheduler integration Date: Mon, 09 Jul 2007 09:32:43 +1000 Message-ID: <1183937563.6005.365.camel@localhost.localdomain> References: <11838994974161-git-send-email-avi@qumranet.com> <20070708133539.GA12597@elte.hu> <4690E973.7000606@qumranet.com> <20070708134850.GB22911@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ingo Molnar Return-path: In-Reply-To: <20070708134850.GB22911-X9Un+BFzKDI@public.gmane.org> 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 Sun, 2007-07-08 at 15:48 +0200, Ingo Molnar wrote: > * Avi Kivity wrote: > > > >>+#ifdef CONFIG_SCHED_KVM > > >>+static __read_mostly struct sched_kvm_hooks kvm_hooks; > > >>+#endif > > > > > >please just add a current->put_vcpu() function pointer instead of > > >this hooks thing. > > > > Won't that increase task_struct (16 bytes on 64-bit) unnecessarily? > > The function pointers are common to all virtual machines. > > well, this function pointer could then be reused by other virtual > machines as well, couldnt it? If the task struct overhead is a problem > (it really isnt, and it's dependent on CONFIG_KVM) then we could switch > it around to a notifier-alike mechanism. OK, this patch is *ugly*. Not that there's anything wrong with a patch which says "I'm going to preempt you", but making it kvm-specific is ugly. ISTR times past where I wanted such a hook, although none spring immediately into my pre-coffee brain. I think a "struct preempt_ops *" and a "void *preempt_ops_data" inside every task struct is a better idea. Call the config option PREEMPT_SCHED_HOOKS and now there's nothing kvm-specific about it... Cheers, Rusty. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/