From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754113AbeDBCqs (ORCPT ); Sun, 1 Apr 2018 22:46:48 -0400 Received: from mail-wm0-f43.google.com ([74.125.82.43]:51107 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754072AbeDBCqq (ORCPT ); Sun, 1 Apr 2018 22:46:46 -0400 X-Google-Smtp-Source: AIpwx48HSBAv2MNO4kJn9lDR4zV4XZZG8DUoVshFDIIQE2mINyQNmSq1k83nLC9lBUJz4EeuecNgvA== Subject: Re: [Qemu-devel] [RFC] About 9pfs support "O_DIRECT + aio"? To: jiangyiwen , Andrew Morton , Eric Van Hensbergen , Ron Minnich , Latchesar Ionkov , Greg Kurz , aneesh.kumar@linux.vnet.ibm.com Cc: v9fs-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org References: <5ABDFB24.1080207@huawei.com> From: Paolo Bonzini Message-ID: <41088460-11f1-1ec7-2bfa-1ebdf675dc17@redhat.com> Date: Mon, 2 Apr 2018 04:45:36 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <5ABDFB24.1080207@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/03/2018 10:53, jiangyiwen wrote: > Currently, I found virtio-9p in VirtFS don't support "O_DIRECT + aio" > mode, both v9fs and qemu. So when user use "O_DIRECT + aio" mode and > increase iodepths, they can't get higher IOPS. > > I want to know why v9fs don't implement this mode? And I will try to > implement this mode from now on. Can you explain? I think 9p has support for direct I/O in Linux. See v9fs_direct_IO in fs/9p/vfs_addr.c. Paolo