Re: performance "regression" in cfq compared to anticipatory, deadline and noop

[Kasper Sandberg <lkml@metanurb.dk>]

On Tue, 2008-05-13 at 15:51 +0200, Kasper Sandberg wrote:
> On Tue, 2008-05-13 at 14:20 +0200, Jens Axboe wrote:
> > On Sun, May 11 2008, Kasper Sandberg wrote:
> > > On Sun, 2008-05-11 at 14:14 +0100, Daniel J Blueman wrote:
> > > > I've been experiencing this for a while also; an almost 50% regression
> > > > is seen for single-process reads (ie sync) if slice_idle is 1ms or
> > > > more (eg default of 8) [1], which seems phenomenal.
> <snip>
> > > 
<snip>
> 
> i expect to get around to doing this this afternoon, or tonight at
> ~02:00
> (im GMT+1).

Well :) not too far off(02:32 now)

http://62.242.235.92/~redeeman/blktrace.tar.bz2

it contains the blktrace with cfq, noop, anticipatory and deadline,
along with the output of blktrace and hdparm.

Hope it helps.

> 
> 
> > 
> > If someone would send me a blktrace of such a slow run, that would be
> > nice. Basically just do a blktrace /dev/sda (or whatever device) while
> > doing the hdparm, preferably storing output files on a difference
> > device. Then send the raw sda.blktrace.* files to me. Thanks!
> > 
> 
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