[lkml]   [2004]   [Sep]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [patch] voluntary-preempt-2.6.9-rc1-bk4-R1
Alan Cox wrote :
> On Mer, 2004-09-08 at 21:33, wrote:
> > >.... Please disable IDE DMA and see
> > >what happens (after hiding the PIO IDE codepath via
> > >touch_preempt_timing()).
> >
> > Not quite sure where to add touch_preempt_timing() calls - somewhere in the
> > loop in ide_outsl and ide_insl? [so we keep resetting the start /end
> > times?]
> If you haven't done hdparm -u1 that may be a reason you want to touch
> these. To defend against some very bad old h/w where a stall in the I/O
> stream to the disk causes corruption we disable IRQ's across the
> transfer in PIO mode by default.

I had the exact same problem showing in the output of latencytest, and
enabling unmaskirq on the drive being stressed solved it, thanks !

See this for the problem :
and this for the (impressive) results :


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 14:06    [from the cache]
©2003-2014 Jasper Spaans. hosted at Digital Ocean