From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=36795 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PP8oS-0000uX-En for qemu-devel@nongnu.org; Sun, 05 Dec 2010 02:15:13 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PP8oP-0003Bp-VY for qemu-devel@nongnu.org; Sun, 05 Dec 2010 02:15:12 -0500 Received: from smtp.ispras.ru ([83.149.198.201]:34976) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PP8oP-00037s-P7 for qemu-devel@nongnu.org; Sun, 05 Dec 2010 02:15:09 -0500 Message-ID: <4CFB3BE4.1090505@ispras.ru> Date: Sun, 05 Dec 2010 10:14:44 +0300 From: Kirill Batuzov MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] Speedup 'tb_find_slow' by using the same heuristic as during memory page lookup References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl Cc: qemu-devel@nongnu.org On 04.12.2010 23:11, Blue Swirl wrote: > On Thu, Dec 2, 2010 at 1:12 PM, Kirill Batuzov wrote: >> Move the last found TB to the head of the list so it will be found more quickly next time it will be looked for. >> >> Signed-off-by: Kirill Batuzov >> Signed-off-by: Pavel Yushchenko >> --- >> >> This patch appeared during investigation of performance issues with >> S5PC110 emulation for Samsung. It increses OS startup speed significantly. > > The patch looks reasonable, but I didn't see any visible difference in > my tests. Could you report your numbers? The exact numbers depend on complexity of guest system. - For basic Debian system (no X-server) on versatilepb we observed 25% decrease of boot time. - For to-be released Samsung LIMO platform on S5PC110 board we observed 2x (for older version) and 3x (for newer version) decrease of boot time. - Small CPU-intensive benchmarks are not affected because they are completely handled by 'tb_find_fast'. We also noticed better response time for heavyweight GUI applications, but I do not know how to measure it accurately. ---- Kirill.