From owner-freebsd-emulation@FreeBSD.ORG Thu May 15 23:43:08 2008 Return-Path: Delivered-To: freebsd-emulation@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E42FD1065675 for ; Thu, 15 May 2008 23:43:08 +0000 (UTC) (envelope-from scf@FreeBSD.org) Received: from mail.farley.org (farley.org [67.64.95.201]) by mx1.freebsd.org (Postfix) with ESMTP id 979148FC2E for ; Thu, 15 May 2008 23:43:08 +0000 (UTC) (envelope-from scf@FreeBSD.org) Received: from thor.farley.org (HPooka@thor.farley.org [192.168.1.5]) by mail.farley.org (8.14.3/8.14.3) with ESMTP id m4FNh6Af024900 for ; Thu, 15 May 2008 18:43:06 -0500 (CDT) (envelope-from scf@FreeBSD.org) Date: Thu, 15 May 2008 18:43:06 -0500 (CDT) From: "Sean C. Farley" To: freebsd-emulation@FreeBSD.org Message-ID: User-Agent: Alpine 1.10 (BSF 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII X-Spam-Status: No, score=-4.4 required=3.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.4 X-Spam-Checker-Version: SpamAssassin 3.2.4 (2008-01-01) on mail.farley.org Cc: Subject: QEMU AIO patch X-BeenThere: freebsd-emulation@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Development of Emulators of other operating systems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 May 2008 23:43:09 -0000 Awhile ago, I wrote a patch to take advantage of FreeBSD's aio_waitcomplete() call in the QEMU raw block code. It took some doing, but I finally found a copy of the patch[1] on a laptop that started dying about a year ago. Using aio_waitcomplete() should reduce the number of context switches present in the current code. I have not truly tested the patch to see how well it helps. Since it is FreeBSD-only, I am posting it here instead of directly to the QEMU mailing list. Sean 1. http://www.farley.org/freebsd/tmp/qemu-aio.patch -- scf@FreeBSD.org