Re: 2.6.4 ext3fs half order of magnitude slower than xfs - bulk write

[Andrew Morton <akpm@osdl.org>]

Matthias Andree <matthias.andree@gmx.de> wrote:
>
> Andrew Morton:
> 
> > It should be possible to generate a simple testcase which demonstrates this
> > problem on that machine.  Is that something you can do?
> > 
> > From your description, write-and-fsync.c from
> > 
> > 	http://www.zip.com.au/~akpm/linux/patches/stuff/ext3-tools.tar.gz
> > 
> > would be a good starting point.
> 
> I've run "write-and-fsync -m SIZE -f SOMEFILE" where size is given in
> each section and SOMEFILE was chosen for some real-life but idle file
> system. I hope this is what you meant. I did one run per test.

Cannot reproduce, sorry.  Kernel is 2.6.5-rc1, disk is a "MAXTOR 6L080J4"


time write-and-fsync -m 256 -f foo

writeback caching off, ext3/ordered:
  write-and-fsync -m 256 -f foo  0.00s user 1.19s system 4% cpu 24.247 total

writeback caching off, XFS:
  write-and-fsync -m 256 -f foo  0.00s user 0.57s system 2% cpu 24.041 total

writeback caching on, ext3/ordered:
  write-and-fsync -m 256 -f foo  0.00s user 1.16s system 14% cpu 8.169 total

writeback caching on, XFS:
  write-and-fsync -m 256 -f foo  0.00s user 0.58s system 8% cpu 6.950 total
  write-and-fsync -m 256 -f foo  0.00s user 0.54s system 6% cpu 8.109 total
  write-and-fsync -m 256 -f foo  0.00s user 0.55s system 5% cpu 10.057 total
  write-and-fsync -m 256 -f foo  0.00s user 0.56s system 8% cpu 6.870 total

(quite some variability in XFS)


So...   Maybe you could test some other disks or something?