[Devel] Re: seems to be a flaw in cfq

[Jens Axboe]

On Thu, Dec 21 2006, Jens Axboe wrote:
> On Thu, Dec 21 2006, Vasily Tarasov wrote:
> > Hello, Jens,
> > 
> > Sorry for late answer.
> > The situation is the following:
> > 
> > direct seqread
> > (2.6.18) - reproducable
> > (2.6.20-rc1) - reproducable
> > (2.6.20-rc1 + your fix) - not reproducable
> > 
> > buffered randread
> > (2.6.18) - reproducable
> > (2.6.20-rc1) - not reproducable
> > (2.6.20-rc1 + your fix) - not reproducable
> > 
> > So the conclusion: problem with "direct seqread" is fixed by your patch
> > (thanks!) and
> > the problem with "buffered randread" was fixed in 2.6.19/2.6.20.
> 
> Perfect, explains why I didn't see much badness with buffered io on
> 2.6.20-rc1'ish. Thanks for retesting and the initial report, the fix I
> sent you is going upstream (sitting in the 'for-linus' branch awaiting a
> pull) for 2.6.20-rc2.

Oh, Linus just pulled a few minutes ago, the fix is already upstream
now.

-- 
Jens Axboe