From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Npby0-0008US-0e for qemu-devel@nongnu.org; Thu, 11 Mar 2010 01:33:56 -0500 Received: from [199.232.76.173] (port=52165 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Npbxy-0008UK-Gu for qemu-devel@nongnu.org; Thu, 11 Mar 2010 01:33:54 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1Npbxx-0005Uw-R8 for qemu-devel@nongnu.org; Thu, 11 Mar 2010 01:33:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46327) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Npbxx-0005Uq-Fo for qemu-devel@nongnu.org; Thu, 11 Mar 2010 01:33:53 -0500 Message-ID: <4B988EBB.1060007@redhat.com> Date: Thu, 11 Mar 2010 08:33:31 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] Inter-VM shared memory PCI device References: <1267833161-25267-1-git-send-email-cam@cs.ualberta.ca> <4B97D349.1030105@codemonkey.ws> <4B97D752.3080700@redhat.com> <201003101741.47300.paul@codesourcery.com> In-Reply-To: <201003101741.47300.paul@codesourcery.com> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Brook Cc: Cam Macdonell , qemu-devel@nongnu.org, kvm@vger.kernel.org On 03/10/2010 07:41 PM, Paul Brook wrote: >>> You're much better off using a bulk-data transfer API that relaxes >>> coherency requirements. IOW, shared memory doesn't make sense for TCG >>> >> Rather, tcg doesn't make sense for shared memory smp. But we knew that >> already. >> > In think TCG SMP is a hard, but soluble problem, especially when you're > running guests used to coping with NUMA. > Do you mean by using a per-cpu tlb? These kind of solutions are generally slow, but tcg's slowness may mask this out. > TCG interacting with third parties via shared memory is probably never going > to make sense. > The third party in this case is qemu. -- error compiling committee.c: too many arguments to function