Re: disk speed regression kernel 2.6.29 and after

[Will <whansard@sbcglobal.net>]

On Thu, 24 Sep 2009 14:26:49 +0200
Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> wrote:

> 
> 
> I don't see how could commit 295f00 be the guilty one here.  I'm suspecting
> that bisection went wrong at some point (easy to verify by checking if commit
> 295f00^1 is also bad).
> 
> PS Will, it would be useful to try libata first and possibly rule out PATA out
> of the picture completely.

Disabling "ATA/ATAPI/MFM/RLL"  restored my performance completely, with the
newer kernels. I'll just have to get used my other hard drives being sdb . . ..
Thanks guys.  The copy takes right at 3m30s now.
I made a change to dd years ago to make it default to 1 meg block size and to show
me the "Megs copied" on screen, so I can watch how fast dd is going.  With the 
older atapi drivers, this copy would be fast, but jerky and halting. With kernel
2.6.29 and after the halts were more frequent and longer, dragging the copy out
to over 9 minutes in this case.  With only the libata enabled, the "megs copied"
is very smooth, with no halting, though still right at 3m30s.
If you need me to test anything for the sake of the older drivers, I can.
Thanks again for the help.