From: Josef Bacik <jbacik@fb.com>
To: Eric Sandeen <sandeen@redhat.com>,
linux-btrfs@vger.kernel.org, xfs@oss.sgi.com
Subject: Re: [PATCH] xfstests: kill lib/random.c
Date: Mon, 6 Jan 2014 16:42:14 -0500 [thread overview]
Message-ID: <52CB2336.2060009@fb.com> (raw)
In-Reply-To: <52CB20ED.1010705@redhat.com>
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 <handwave> 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,
Josef
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2014-01-06 21:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-06 19:58 [PATCH] xfstests: kill lib/random.c Josef Bacik
2014-01-06 21:32 ` Eric Sandeen
2014-01-06 21:42 ` Josef Bacik [this message]
2014-01-06 21:46 ` Eric Sandeen
2014-01-07 20:01 ` Ben Myers
2014-01-07 20:10 ` Eric Sandeen
2014-01-07 20:15 ` Eric Sandeen
2014-01-07 20:15 ` Josef Bacik
2014-01-07 20:40 ` Ben Myers
2014-01-07 21:17 ` Josef Bacik
2014-01-07 21:20 ` Chris Mason
2014-01-13 1:56 ` Dave Chinner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=52CB2336.2060009@fb.com \
--to=jbacik@fb.com \
--cc=linux-btrfs@vger.kernel.org \
--cc=sandeen@redhat.com \
--cc=xfs@oss.sgi.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).