Re: Silicon Image 3112A SATA trouble

[Jens Axboe <axboe@suse.de>]

On Sun, Nov 30 2003, Bartlomiej Zolnierkiewicz wrote:
> 
> I read it _very_ closely, here is your original mail with subject
> "Re: 2.6.0-test9 /-mm3 SATA siimage - bad disk performance":
> 
> On Saturday 15 of November 2003 10:11, Prakash K. Cheemplavam wrote:
> > Marcus Hartig wrote:
> > > Hello all,
> > >
> > > with the Fedora 1 kernel 2.4.22-1.2115.nptl I get with hdparm -t
> > > (Timing buffered disk reads) 34 MB/sec. Its very slow for this drive.
> > >
> > > With 2.6.0-test9 and -mm3 I get around "62 MB in 3.05 = 20,31". Wow"
> > > Back to ~1998?
> >
> > I have a similar problem: With 2.4.22-ac3 I had 37mb/sec with my Samsung
> > HD and 49MB/sec with IBM/Hitachi, now with 2.6 (all I tried, including
>                                     ^^^^^^^^^^^^
> > test9-mm2) I had only 20mb/sec for Samsung and about 39mb/sec for the
>              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > IBM. Motherboard is Abit NF7-S Rev2.0, as well, so same situation with
>   ^^^^
> > the siimage 1.06 driver. I wanted to run some dd tests as well, but it 
> > is a real performance hit. Playing with readahead or other hdparm
> > options didn't help either.
> >
> > Prakash
> 
> In 2.6.x there is no max_kb_per_request setting in /proc/ide/hdx/settings.
> Therefore
> 	echo "max_kb_per_request:128" > /proc/ide/hde/settings
> does not work.
> 
> Hmm. actually I was under influence that we have generic ioctls in 2.6.x,
> but I can find only BLKSECTGET, BLKSECTSET was somehow lost.  Jens?

Probably because it's very dangerous to expose, echo something too big
and watch your data disappear.

-- 
Jens Axboe