From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 9A2877F37 for ; Mon, 6 Jan 2014 15:47:05 -0600 (CST) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay2.corp.sgi.com (Postfix) with ESMTP id 86F4A304039 for ; Mon, 6 Jan 2014 13:47:05 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id YJmBXis3CcaXv1Fm for ; Mon, 06 Jan 2014 13:47:00 -0800 (PST) Message-ID: <52CB2452.70507@redhat.com> Date: Mon, 06 Jan 2014 15:46:58 -0600 From: Eric Sandeen MIME-Version: 1.0 Subject: Re: [PATCH] xfstests: kill lib/random.c References: <1389038323-8304-1-git-send-email-jbacik@fb.com> <52CB20ED.1010705@redhat.com> <52CB2336.2060009@fb.com> In-Reply-To: <52CB2336.2060009@fb.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Josef Bacik , linux-btrfs@vger.kernel.org, xfs@oss.sgi.com On 1/6/14, 3:42 PM, Josef Bacik wrote: > > On 01/06/2014 04:32 PM, Eric Sandeen wrote: >> On 1/6/14, 1:58 PM, Josef Bacik wrote: >>> I was trying to reproduce something with fsx and I noticed that no matter what >>> seed I set I was getting the same file. Come to find out we are overloading >>> random() with our own custom horribleness for some unknown reason. So nuke the >>> damn thing from orbit and rely on glibc's random(). With this fix the -S option >>> actually does something with fsx. Thanks, >> Hm, old comments seem to indicate that this was done to make random >> behave the same on different architectures (i.e. same result from same seed, >> I guess?) I . . . don't know if that is true of glibc's random(), is it? >> >> I'd like to dig into the history just a bit before we yank this, just to >> be sure. > > I think that if we need the output to match based on a predictable > random() output then we've lost already. We shouldn't be checking for > specific output (like inode numbers or sizes etc) that are dependant > on random()'s behaviour, and if we are we need to fix those tests. So > even if that is why it was put in place originally I'd say it is high > time we ripped it out and fixed up any tests that rely on this > behaviour. Thanks, Yeah, you're probably right. And the ancient xfstests history seems to be lost in the mists of time, at least as far as I can see. So I'm ok with this but let's let Dave & SGI chime in too just to be certain. Thanks, -Eric > Josef _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs