Subject: Re: CVS commit: pkgsrc/benchmarks/bytebench
To: Urban Boquist <>
From: Todd Vierling <>
List: tech-pkg
Date: 11/01/2005 22:16:27
On Tue, 1 Nov 2005, Urban Boquist wrote:

> Todd> While there, use fsync(2) on all hosts.  Without this, the
> Todd> fstime benchmark will be disproportionately biased toward OS's
> Todd> and hardware that buffer larger amounts of data in memory before
> Todd> [background] syncing.

> the second part of this change seems inappropriate, IMHO. The
> benchmark may be biased, but that is not up to pkgsrc to
> decide. Pkgsrc is just supposed to be a way to port software, it
> should not change the behavior of an old and well defined benchmark.

Actually, I just disproved fstime's methodology.  Without using fsync(2),
the numbers are *meaningless*.  Testing filesystem speed accurately requires
actually writing to the disk -- and if you don't fsync(2), you can very well
end up with a "write speed" of one or two orders of magnitude higher than a
disk is physically capable of performing.

It should wither get fsync(2), or be removed from the battery of tests.  We
should not be providing a bogus test in a supplied benchmark program.

-- Todd Vierling <> <> <>