From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KyTPW-00067s-6A for qemu-devel@nongnu.org; Fri, 07 Nov 2008 10:38:10 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KyTPU-00066p-2a for qemu-devel@nongnu.org; Fri, 07 Nov 2008 10:38:09 -0500 Received: from [199.232.76.173] (port=53373 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KyTPT-00066m-Tm for qemu-devel@nongnu.org; Fri, 07 Nov 2008 10:38:07 -0500 Received: from hs-out-0708.google.com ([64.233.178.244]:11658) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1KyTPT-0007oP-JV for qemu-devel@nongnu.org; Fri, 07 Nov 2008 10:38:07 -0500 Received: by hs-out-0708.google.com with SMTP id k27so624515hsc.2 for ; Fri, 07 Nov 2008 07:38:05 -0800 (PST) Message-ID: <491460D2.4060203@codemonkey.ws> Date: Fri, 07 Nov 2008 09:37:54 -0600 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 0/4] qcow2: Improve cluster refcount update References: <1225990556.6576.10.camel@frecb07144> <49133D17.3050100@codemonkey.ws> <1226047453.4046.4.camel@frecb07144> <491449C4.4070500@codemonkey.ws> <1226070063.4046.56.camel@frecb07144> In-Reply-To: <1226070063.4046.56.camel@frecb07144> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 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 Laurent Vivier wrote: > Le vendredi 07 novembre 2008 à 07:59 -0600, Anthony Liguori a écrit : > > In all cases #1 is totally useless as it is only cosmetic. > > #2 improves performance without aligned buffers and with "cache" set to > default value. > I'm currently rewriting the block-raw-posix.c O_DIRECT support. I'll commit your patches once I finish that. I'm switching everything to use the aio functions, introducing a memory pool so that we can efficiently allocate memory for new requests without having unbounded memory allocation, and switching all the synchronous functions to use the aio functions. Regards, Anthony Liguori > I've installed ubuntu 8.04 desktop on an empty qcow2 file using qemu: > > without patch: 16 minutes 54 seconds > with patch: 15 minutes 44 seconds > > Regards, > Laurent >