From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <533E1172.6010803@kernel.dk> Date: Thu, 03 Apr 2014 19:57:06 -0600 From: Jens Axboe MIME-Version: 1.0 Subject: Re: ioengine=sync issue on Windows References: <8a71414766f34cfe98805c5dd2e94d2e@DB4PR03MB572.eurprd03.prod.outlook.com> <53208C60.8090708@kernel.dk> <533B7FC4.70700@cran.org.uk> <533DE3DC.6020605@cran.org.uk> In-Reply-To: <533DE3DC.6020605@cran.org.uk> Content-Type: text/plain; charset="iso-8859-1"; format="flowed" Content-Transfer-Encoding: quoted-printable To: Bruce Cran , =?ISO-8859-1?Q?S=E9bastien_Bouchex_?= =?ISO-8859-1?Q?Bellomi=E9?= , "fio@vger.kernel.org" , bcran@fusionio.com List-ID: On 2014-04-03 16:42, Bruce Cran wrote: > > On 4/1/2014 9:11 PM, Bruce Cran wrote: >> >> On 3/12/2014 10:33 AM, Jens Axboe wrote: >>> On 03/12/2014 09:41 AM, S=EF=BF=BDbastien Bouchex Bellomi=EF=BF=BD wrot= e: >>>> >>>> fio: pid=3D5144, err=3D5/file:backend.c:768, func=3Dfull resid, >>>> error=3DInput/output error >>>> >>>> random_read: (groupid=3D0, jobs=3D1): err=3D 5 (file:backend.c:768, >>>> func=3Dfull resid, error=3DInput/output error): pid=3D5144: Wed Mar 12 >>>> 16:36:45 2014 >>> Bruce, do you know why that is? >>> >> >> It appears to be because after seeking, there's 92 bytes before a >> space in the file (i.e. it's a sparse file), and instead of filling >> the buffer with 0's read() is for some reason returning 0. >> > > I was wrong. The problem has something to do with fil_io_buffer - and > in particular __fill_random_buf. The io error disappears if I change the > line: > > *ptr =3D seed; > to > *ptr =3D 1; > > Also, fio-2.0.15 works, while fio-2.1 doesn't. That makes very little sense... How could the contents of the buffer=20 change the behavior? Could you run a git bisect? Should be quick'n easy, if it's nicely=20 reproducible. --=20 Jens Axboe