Re: Nasty IDE crasher in 2.6.9rc1

[Jens Axboe <axboe@suse.de>]

On Fri, Sep 03 2004, Alan Cox wrote:
> On Gwe, 2004-09-03 at 15:50, Jens Axboe wrote:
> > (suse.dk is not related to suse.de and it helpfully eats all messages
> > sent to unknown users. not so great :(
> 
> Ah sorry.
> 
> > > Another problem with barrier is that it can take several minutes worst case
> > > for the command to complete on a large modern drive (timings c/o friendly
> > > ide drive engineer). That causes two problems I've pointed out to Jens that
> > > we need to fix before barriers are IMHO production grade
> > 
> > Can you pass me his results?
> 
> I can ask. Its NDA data (not Maxtor). Or Eric might have public info ?
> The later mail I reported my tests trying to make it as slow as possible
> and I couldn't get worse than 7 seconds for the command.

IIRC, 7 seconds is the magic number that Microsoft uses for when a
command times out in the kernel... That might make the results a little
suspicious :)

> 
> > > 2.	The timeouts on the command issue appear to be too small, and
> > > 	we will time out and reset the drive in loaded situations. 
> > 
> > You don't seem to address that in your patch?
> 
> I'm not sure what the right answer is.

I guess as a first measure just increasing the timeout two-fold will
cover most of the problem.

-- 
Jens Axboe