From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1IETsw-0005Ti-IP for qemu-devel@nongnu.org; Fri, 27 Jul 2007 13:45:54 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1IETsu-0005OD-PE for qemu-devel@nongnu.org; Fri, 27 Jul 2007 13:45:53 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IETsu-0005Nn-Db for qemu-devel@nongnu.org; Fri, 27 Jul 2007 13:45:52 -0400 Received: from mail.codesourcery.com ([65.74.133.4]) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1IETst-0001Qq-TC for qemu-devel@nongnu.org; Fri, 27 Jul 2007 13:45:52 -0400 From: Paul Brook Subject: Re: QEMU Automated Testing (was [Qemu-devel] qemu Makefile.target vl.h hw/acpi.c hw/adlib.c ...) Date: Fri, 27 Jul 2007 18:38:19 +0100 References: <685454.54168.qm@web54108.mail.re2.yahoo.com> In-Reply-To: <685454.54168.qm@web54108.mail.re2.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707271838.20201.paul@codesourcery.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: n schembr > >As Qemu cannot use multicore CPUs (partially due to missing thread > >safety), yet, you won't benefit from this unless you want to run > >multiple instances of Qemu in parallel. > > how close is thread safey? In a useful form: a fair way off. It's relatively simple to hack something together than runs. Making it work correctly and go fast is much harder though. My current prototype (running on 2 cores) runs about a quarter the speed of normal qemu, and dies shortly after booting because the guest atomic synchronisation primitives don't work right. Either way, for a tinderbox or automated testing yo *do* have lots of different tests you can run in parallel, so it doesn't matter that each qemu instance only uses one core. We're only talking about small SMP here - maybe 16 cores, but not thousands. Paul