Re: 2.6.12-rc6-mm1 & 2K lun testing

Andrew Morton
2005-06-17T21:12:44Z

Badari Pulavarty <pbadari@us.ibm.com> wrote:
>
> > It shouldn't be necessary to do both. Either the patch or the tuning
> > should fix it. Please confirm.
> >
> > Also please determine whether the deep CFQ queue depth is a problem when
> > the VFS tuning/patching is in place.
> >
> > IOW: let's work out which of these three areas needs to be addressed.
> >
>
> Andrew,
>
> Sorry for not getting back earlier. I am running into weird problems.
> When running "dd" write tests to 2048 ext3 filesystems, just with your
> patch (no dirty ratio or CFS queue depth tuning), I see "buff"
> increasing instead of "cache" and I see "bi" instead of "bo".
> Whats going on here ?

Beats me. Are you sure you're not running a broken vmstat?

`buff' would increase if you were accidentally writing to /dev/sda1 rather
than /dev/sda1/some-filename, but I don't know why vmstat would be getting
confused over the direction of the I/O.

>
> procs -----------memory---------- ---swap-- -----io---- --system--
> ----cpu----
> r b swpd free buff cache si so bi bo in cs us
> sy id wa
> ..
> 2 0 4 6339920 42712 24884 0 0 0 19 413 1237 46
> 6 48 0

You're wordwrapping...