From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1HFWVd-0004t1-NP for qemu-devel@nongnu.org; Fri, 09 Feb 2007 09:13:53 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1HFWVc-0004pW-B3 for qemu-devel@nongnu.org; Fri, 09 Feb 2007 09:13:52 -0500 Received: from mx1.polytechnique.org ([129.104.30.34]) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA:32) (Exim 4.52) id 1HFWVc-0003J5-0l for qemu-devel@nongnu.org; Fri, 09 Feb 2007 09:13:52 -0500 Message-ID: <45CC8195.1030404@bellard.org> Date: Fri, 09 Feb 2007 15:13:41 +0100 From: Fabrice Bellard MIME-Version: 1.0 Subject: Re: [Qemu-devel] Xenoppix (KNOPPIX5.1.1 + Xen3.0.4 + QEMU/KVM + HTTP-FUSE) is released References: <20070209.194958.123996617.k.suzaki@aist.go.jp> <45CC5063.60504@bellard.org> <20070209.202151.55858230.k.suzaki@aist.go.jp> In-Reply-To: <20070209.202151.55858230.k.suzaki@aist.go.jp> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: k.suzaki@aist.go.jp Cc: qemu-devel@nongnu.org Kuniyasu Suzaki wrote: > [...] > >>2) For best performances with kqemu, it is better to use Linux 2.4 as > >>guest OS (I know this is far from acceptable, but it can help some > >>people to get better performance !). > > Please tell me the reason why Linux 2.4 shows better performance, if > you have time. Does the difference of clock tick cause the problem? The Linux 2.6 kernel has more code running with the interrupts disabled than the 2.4 one. kqemu interprets the x86 code when the interrupts are disabled, so it is very slow in this case. A potential solution I am investigating is to use the new paravirtualization API of the kernel versions >= 2.6.20. Regards, Fabrice.