From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f179.google.com ([209.85.213.179]:34258 "EHLO mail-ig0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753069AbbLJG4A (ORCPT ); Thu, 10 Dec 2015 01:56:00 -0500 Received: by mail-ig0-f179.google.com with SMTP id g19so10224268igv.1 for ; Wed, 09 Dec 2015 22:56:00 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: Date: Thu, 10 Dec 2015 06:56:00 +0000 Message-ID: Subject: Re: io_size usage From: Sitsofe Wheeler Content-Type: text/plain; charset=UTF-8 Sender: fio-owner@vger.kernel.org List-Id: fio@vger.kernel.org To: Jun He Cc: "fio@vger.kernel.org" Hi, Your job sets and io_size four times that of "size" of the disk that you are using. This will force your I/O to wrap abound to the start of the region (why not use loops?). Are you saying that you think the sync job's iolog is wrong because it only says it performed one loop? On 9 December 2015 at 02:50, Jun He wrote: > Hi all, > I think there is a bug for io_size. > > For example, I want to write 16KB data to a file of size 8KB (so each block is > written twice) and I have the following job file: > > [global] > ioengine=sync > rw=write > bs=4kb > size=8kb > io_size=32kb > > [job1] > write_iolog=iolog.1 > > > After running, iolog.1 will contain the following contents: > > fio version 2 iolog > job1.0.0 add > job1.0.0 open > job1.0.0 write 0 4096 > job1.0.0 write 4096 4096 > job1.0.0 close > > This shows that each block has been only written once. > > If I change the ioengine to libaio, iolog.1 will contain: > > fio version 2 iolog > job1.0.0 add > job1.0.0 open > job1.0.0 write 0 4096 > job1.0.0 write 4096 4096 > job1.0.0 close > job1.0.0 open > job1.0.0 write 0 4096 > job1.0.0 write 4096 4096 > job1.0.0 close > job1.0.0 open > job1.0.0 write 0 4096 > job1.0.0 write 4096 4096 > job1.0.0 close > job1.0.0 open > job1.0.0 write 0 4096 > job1.0.0 write 4096 4096 > job1.0.0 close > > > Bug or wrong usage? > > Thanks, > Jun > > > > -- > To unsubscribe from this list: send the line "unsubscribe fio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Sitsofe | http://sucs.org/~sits/