Re: Time sliced CFQ io scheduler

[Jens Axboe <axboe@suse.de>]

On Fri, Dec 03 2004, Prakash K. Cheemplavam wrote:
> Jens Axboe schrieb:
> >On Thu, Dec 02 2004, Prakash K. Cheemplavam wrote:
> >
> 
> >>0  3   3080   2208   1156 817712    0    0  3592 75624 1326  2289  1 36  
> >>0 63
> >>0  3   3080   2664   1156 818240    0    0  5124 15692 1302   992  1 18  
> >>0 81
> >>0  3   3080   2580   1160 815832    0    0  4356 155792 1375  1064  1 39  
> >>0 60
> >>0  3   3080   2472   1160 817124    0    0  3076 100852 1345  1138  1 23  
> >>0 76
> >>2  4   3080   2836   1148 816228    0    0  3336 100412 1352  1379  1 47  
> >>0 52
> >>0  4   3080   2708   1144 815964    0    0  3844 48908 1343   871  1 25  
> >>0 74
> >>0  3   3080   2748   1152 815984    0    0  3332 71996 1338   843  1 27  
> >>0 72
> >
> >
> >Can you try with the patch that is in the parent of this thread? The
> >above doesn't look that bad, although read performance could be better
> >of course. But try with the patch please, I'm sure it should help you
> >quite a lot.
> >
> 
> It actually got worse: Though the read rate seems accepteble, it is not, as 
> interactivity is dead while writing. I cannot start porgrammes, other 
> programmes which want to do i/o pretty much hang. This is only while 
> writing. While reading there is no such problem.

Interesting, thanks for testing. I'll run some tests here as well, so
far only the cases mentioned yesterday have been tested.

You could try and bumb the slice period. But I'll experiment and see
what happens. What is your test case?

-- 
Jens Axboe