From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Kltte-0006Zg-EA for qemu-devel@nongnu.org; Fri, 03 Oct 2008 19:17:18 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Klttc-0006YF-Vy for qemu-devel@nongnu.org; Fri, 03 Oct 2008 19:17:18 -0400 Received: from [199.232.76.173] (port=41740 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Klttc-0006Xt-PC for qemu-devel@nongnu.org; Fri, 03 Oct 2008 19:17:16 -0400 Received: from mail.codesourcery.com ([65.74.133.4]:40734) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1Klttc-0006um-BC for qemu-devel@nongnu.org; Fri, 03 Oct 2008 19:17:16 -0400 From: Paul Brook Subject: Re: [Qemu-devel] [PATCH 4/4] Reallocate dma buffers in read/write path if needed Date: Sat, 4 Oct 2008 00:17:08 +0100 References: <1223071531-31817-1-git-send-email-ryanh@us.ibm.com> <1223071531-31817-5-git-send-email-ryanh@us.ibm.com> In-Reply-To: <1223071531-31817-5-git-send-email-ryanh@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200810040017.09081.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: Anthony Liguori , Ryan Harper , kvm@vger.kernel.org On Friday 03 October 2008, Ryan Harper wrote: > The default buffer size breaks up larger read/write requests unnecessarily. > When we encounter requests larger than the default dma buffer, reallocate > the buffer to support the request. Allocating unboundedly large host buffers based on guest input seems like a bad idea. Paul