Re: pluggable scheduler thread (was Re: Volanomark slows by 80% under CFS)

Tim Chen
2007-07-30T20:43:18Z

On Sat, 2007-07-28 at 02:51 -0400, Chris Snook wrote:

>
> Tim --
>
> Since you're already set up to do this benchmarking, would you mind
> varying the parameters a bit and collecting vmstat data? If you want to
> run oprofile too, that wouldn't hurt.
>

Here's the vmstat data. The number of runnable processes are
fewer and there're more contex switches with CFS.

The vmstat for 2.6.22 looks like

procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
r b swpd free buff cache si so bi bo in cs us sy id wa st
391 0 0 1722564 14416 95472 0 0 169 25 76 6520 3 3 89 5 0
400 0 0 1722372 14416 95496 0 0 0 0 264 641685 47 53 0 0 0
368 0 0 1721504 14424 95496 0 0 0 7 261 648493 46 51 3 0 0
438 0 0 1721504 14432 95496 0 0 0 2 264 690834 46 54 0 0 0
400 0 0 1721380 14432 95496 0 0 0 0 260 657157 46 53 1 0 0
393 0 0 1719892 14440 95496 0 0 0 6 265 671599 45 53 2 0 0
423 0 0 1719892 14440 95496 0 0 0 15 264 701626 44 56 0 0 0
375 0 0 1720240 14472 95504 0 0 0 72 265 671795 43 53 3 0 0
393 0 0 1720140 14480 95504 0 0 0 7 265 733561 45 55 0 0 0
355 0 0 1716052 14480 95504 0 0 0 0 260 670676 43 54 3 0 0
419 0 0 1718900 14480 95504 0 0 0 4 265 680690 43 55 2 0 0
396 0 0 1719148 14488 95504 0 0 0 3 261 712307 43 56 0 0 0
395 0 0 1719148 14488 95504 0 0 0 2 264 692781 44 54 1 0 0
387 0 0 1719148 14492 95504 0 0 0 41 268 709579 43 57 0 0 0
420 0 0 1719148 14500 95504 0 0 0 3 265 690862 44 54 2 0 0
429 0 0 1719396 14500 95504 0 0 0 0 260 704872 46 54 0 0 0
460 0 0 1719396 14500 95504 0 0 0 0 264 716272 46 54 0 0 0
419 0 0 1719396 14508 95504 0 0 0 3 261 685864 43 55 2 0 0
455 0 0 1719396 14508 95504 0 0 0 0 264 703718 44 56 0 0 0
395 0 0 1719372 14540 95512 0 0 0 64 265 692785 45 54 1 0 0
424 0 0 1719396 14548 95512 0 0 0 10 265 732866 45 55 0 0 0

While 2.6.23-rc1 look like
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
r b swpd free buff cache si so bi bo in cs us sy id wa st
23 0 0 1705992 17020 95720 0 0 0 0 261 1010016 53 42 5 0 0
7 0 0 1706116 17020 95720 0 0 0 13 267 1060997 52 41 7 0 0
5 0 0 1706116 17020 95720 0 0 0 28 266 1313361 56 41 3 0 0
19 0 0 1706116 17028 95720 0 0 0 8 265 1273669 55 41 4 0 0
18 0 0 1706116 17032 95720 0 0 0 2 262 1403588 55 41 4 0 0
23 0 0 1706116 17032 95720 0 0 0 0 264 1272561 56 40 4 0 0
14 0 0 1706116 17032 95720 0 0 0 0 262 1046795 55 40 5 0 0
16 0 0 1706116 17032 95720 0 0 0 0 260 1361102 58 39 4 0 0
4 0 0 1706224 17120 95724 0 0 0 126 273 1488711 56 41 3 0 0
24 0 0 1706224 17128 95724 0 0 0 6 261 1408432 55 41 4 0 0
3 0 0 1706240 17128 95724 0 0 0 48 273 1299203 54 42 4 0 0
16 0 0 1706240 17132 95724 0 0 0 3 261 1356609 54 42 4 0 0
5 0 0 1706364 17132 95724 0 0 0 0 264 1293198 58 39 3 0 0
9 0 0 1706364 17132 95724 0 0 0 0 261 1555153 56 41 3 0 0
13 0 0 1706364 17132 95724 0 0 0 0 264 1160296 56 40 4 0 0
8 0 0 1706364 17132 95724 0 0 0 0 261 1388909 58 38 4 0 0
18 0 0 1706364 17132 95724 0 0 0 0 264 1236774 56 39 5 0 0
11 0 0 1706364 17136 95724 0 0 0 2 261 1360325 57 40 3 0 0
5 0 0 1706364 17136 95724 0 0 0 1 265 1201912 57 40 3 0 0
8 0 0 1706364 17136 95724 0 0 0 0 261 1104308 57 39 4 0 0
7 0 0 1705976 17232 95724 0 0 0 127 274 1205212 58 39 4 0 0

Tim