Re: xterm scrolling speed - scheduling weirdness in 2.6 ?!

From: Willy Tarreau
Date: Sun Jan 04 2004 - 07:20:49 EST



Now testing Con's noint patch against 2.6.0. It returns somewhat simmilar
results to Nick's w29p2, and behaves normally. The only noticeable difference
is that a simple task like "while :; do :; done&" eats about 100ms each second,
so if you start 10 of these, you're able to type only once a second (tested).
But I understand that this 'dumbness' was exactly the goal of this patch.
I think that I'll try to use 2.6 + Nick's scheduler for some time on my
notebook to get an overall idea on how it behaves.

BTW, Nick, does your patch rely on -mm1 exclusive features, or would it be
possible to back-port it to plain 2.6 ?

Cheers,
Willy

1) X not reniced.
=================

noint$ time xterm -e seq 1 5000

real 0m0.548s
user 0m0.267s
sys 0m0.052s

noint$ time xterm -e sh -c "ls -l incoming tmp"

real 0m0.974s
user 0m0.481s
sys 0m0.091s

2) Now renicing X to -10
========================

noint$ time xterm -e sh -c "ls -l incoming tmp"

real 0m0.997s
user 0m0.471s
sys 0m0.101s

noint$ time xterm -e seq 1 5000

real 0m0.390s
user 0m0.261s
sys 0m0.058s

3) Now renicing X to +10 to compare with my previous tests
==========================================================

noint$ time xterm -e seq 1 5000

real 0m0.452s
user 0m0.257s
sys 0m0.070s

noint$ time xterm -e sh -c "ls -l incoming tmp"

real 0m0.956s
user 0m0.441s
sys 0m0.091s

noint$ time find incoming tmp |wc -l
204276

real 0m0.914s
user 0m0.257s
sys 0m0.653s

noint$ time xterm -e sh -c "find incoming tmp"

real 0m23.107s
user 0m5.652s
sys 0m1.631s

top - 12:56:42 up 9 min, 5 users, load average: 0.61, 0.54, 0.26
Tasks: 59 total, 3 running, 56 sleeping, 0 stopped, 0 zombie
Cpu(s): 24.8% user, 8.9% system, 66.3% nice, 0.0% idle, 0.0% IO-wait
Mem: 515292k total, 217816k used, 297476k free, 94344k buffers
Swap: 265064k total, 0k used, 265064k free, 45236k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ Command
239 root 30 10 23632 13m 11m R 66.2 2.7 0:11.11 X
374 root 20 0 4764 2660 3844 S 24.7 0.5 0:01.22 xterm
375 willy 20 0 1420 540 1252 S 7.9 0.1 0:00.35 find
373 root 20 0 1692 940 1556 R 1.0 0.2 0:00.08 top

4) Same with renice -15 :
=========================

noint$ time xterm -e sh -c "find incoming tmp"

real 0m22.622s
user 0m5.681s
sys 0m1.807s

top - 12:57:45 up 10 min, 5 users, load average: 0.33, 0.48, 0.26
Tasks: 59 total, 3 running, 56 sleeping, 0 stopped, 0 zombie
Cpu(s): 88.8% user, 11.2% system, 0.0% nice, 0.0% idle, 0.0% IO-wait
Mem: 515292k total, 217880k used, 297412k free, 94404k buffers
Swap: 265064k total, 0k used, 265064k free, 45236k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ Command
239 root 5 -15 23632 13m 11m S 64.3 2.7 0:25.55 X
380 root 20 0 4764 2660 3844 R 26.1 0.5 0:00.82 xterm
381 willy 20 0 1420 540 1252 S 7.5 0.1 0:00.23 find


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