From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [RFC] vhost-blk implementation Date: Thu, 25 Mar 2010 11:48:05 -0400 Message-ID: <20100325154805.GA1504@infradead.org> References: <1269306023.7931.72.camel@badari-desktop> <4BA891E2.9040500@redhat.com> <20100324200502.GB22272@infradead.org> <4BAB02AF.7040308@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , Badari Pulavarty , kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from bombadil.infradead.org ([18.85.46.34]:59525 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750938Ab0CYPsI (ORCPT ); Thu, 25 Mar 2010 11:48:08 -0400 Content-Disposition: inline In-Reply-To: <4BAB02AF.7040308@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Mar 25, 2010 at 08:29:03AM +0200, Avi Kivity wrote: > We still have a virtio implementation in userspace for file-based images. > > In any case, the file APIs are not asynchronous so we'll need a thread > pool. That will probably minimize the difference in performance between > the userspace and kernel implementations. The kernel has "real" aio when doing direct I/O, although currently we can't easily use it from kernelspace. Thejre's a few people who've been looking into making it usable for that, though.