Nicks's scheduler's OK [was Re: xterm scrolling speed - scheduling weirdness in 2.6 ?!]
From: Willy Tarreau
Date: Sun Jan 04 2004 - 06:49:00 EST
On Sun, Jan 04, 2004 at 08:17:24PM +1100, Nick Piggin wrote:
>
> Or, out of interest, an alternate scheduler?
>
> http://www.kerneltrap.org/~npiggin/w29p2.gz
> (applies 2.6.1-rc1-mm1, please renice X to -10 or so)
Nick's scheduler seems rather interesting. X is nearly insensible to renice
as it was in 2.4. I cannot get a slow scrolling anymore except with xterm +j.
And the differences in time between renice -15 and renice +10 are about 5%,
which is perfectly acceptable to me. I got back the 2.4 behaviour (= a usable
desktop). Now recompiling Con's "noint" patch on 2.6.0 for reference.
Cheers,
Willy
1) X not reniced.
=================
w29p2$ time xterm -e seq 1 5000
real 0m0.487s
user 0m0.244s
sys 0m0.075s
w29p2$ time xterm -e sh -c "ls -l incoming tmp"
real 0m1.000s
user 0m0.491s
sys 0m0.106s
2) Now renicing X to -10 as suggested by Nick
=============================================
w29p2$ time xterm -e sh -c "ls -l incoming tmp"
real 0m0.998s
user 0m0.476s
sys 0m0.126s
w29p2$ time xterm -e seq 1 5000
real 0m0.420s
user 0m0.276s
sys 0m0.082s
3) Now renicing X to +10 to compare with my previous tests
==========================================================
w29p2$ time xterm -e seq 1 5000
real 0m0.528s
user 0m0.282s
sys 0m0.056s
w29p2$ time xterm -e sh -c "ls -l incoming tmp"
real 0m0.967s
user 0m0.498s
sys 0m0.111s
w29p2$ time find incoming tmp |wc -l
204276
real 0m0.937s
user 0m0.299s
sys 0m0.593s
w29p2$ time xterm -e sh -c "find incoming tmp"
real 0m21.368s
user 0m5.838s
sys 0m1.341s
top - 12:31:23 up 11 min, 6 users, load average: 0.59, 0.68, 0.39
Tasks: 61 total, 2 running, 59 sleeping, 0 stopped, 0 zombie
Cpu(s): 29.1% user, 6.8% system, 64.1% nice, 0.0% idle, 0.0% IO-wait
Mem: 515248k total, 231160k used, 284088k free, 99172k buffers
Swap: 265064k total, 0k used, 265064k free, 45328k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ Command
302 root 50 10 21500 11m 11m R 63.9 2.3 1:41.67 X
475 root 37 0 4764 2660 3844 S 31.0 0.5 0:01.68 xterm
476 willy 39 0 1420 540 1252 S 3.9 0.1 0:00.23 find
1 root 25 0 348 192 316 S 0.0 0.0 0:05.06 init
2 root 41 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/0
3 root 12 -10 0 0 0 S 0.0 0.0 0:00.20 events/0
4 root 16 -10 0 0 0 S 0.0 0.0 0:00.03 kblockd/0
4) Same with renice -15 :
=========================
w29p2$ time xterm -e sh -c "find incoming tmp"
real 0m19.147s
user 0m5.085s
sys 0m1.238s
top - 12:33:33 up 13 min, 6 users, load average: 0.65, 0.68, 0.42
Tasks: 61 total, 4 running, 57 sleeping, 0 stopped, 0 zombie
Cpu(s): 93.1% user, 6.9% system, 0.0% nice, 0.0% idle, 0.0% IO-wait
Mem: 515248k total, 233464k used, 281784k free, 99540k buffers
Swap: 265064k total, 0k used, 265064k free, 45992k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ Command
302 root 24 -15 21500 11m 11m R 66.2 2.3 2:08.25 X
482 root 40 0 4764 2660 3844 R 29.2 0.5 0:01.50 xterm
483 willy 37 0 1420 540 1252 R 4.9 0.1 0:00.25 find
1 root 26 0 348 192 316 S 0.0 0.0 0:05.06 init
2 root 41 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/0
3 root 12 -10 0 0 0 S 0.0 0.0 0:00.21 events/0
4 root 15 -10 0 0 0 S 0.0 0.0 0:00.03 kblockd/0
5 root 39 0 0 0 0 S 0.0 0.0 0:00.00 pdflush
6 root 23 0 0 0 0 S 0.0 0.0 0:00.00 pdflush
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