4.3 group scheduling regression

From: Mike Galbraith
Date: Sun Oct 11 2015 - 13:42:43 EST


(change subject, CCs)

On Sun, 2015-10-11 at 04:25 +0200, Mike Galbraith wrote:

> > Is the interactivity the same (horrible) at fe32d3cd5e8e (ie, before the
> > load tracking rewrite from Yuyang)?

It is the rewrite, 9d89c257dfb9c51a532d69397f6eed75e5168c35.

Watching 8 single hog groups vs 1 tbench group, master vs 4.2.3, I saw
no big hairy difference, just as 1 group of 8 hogs vs 8 groups of 1.

8 single hog groups vs the less hungry mplayer otoh is quite different

100 second scripted recordings:
(note: "testo" is kde konsole acting as task group launch vehicle)

master
-----------------------------------------------------------------------------------------------------------------
Task | Runtime ms | Switches | Average delay ms | Maximum delay ms | Maximum delay at |
-----------------------------------------------------------------------------------------------------------------
oink:(8) | 787637.964 ms | 16242 | avg: 0.557 ms | max: 68.993 ms | max at: 239.126118 s
mplayer:(25) | 5477.234 ms | 8504 | avg: 16.395 ms | max: 2100.233 ms | max at: 282.850734 s
Xorg:997 | 1773.218 ms | 4680 | avg: 4.857 ms | max: 1640.194 ms | max at: 285.660210 s
konsole:1789 | 649.323 ms | 1261 | avg: 6.747 ms | max: 156.282 ms | max at: 265.548523 s
testo:(9) | 454.046 ms | 2867 | avg: 5.961 ms | max: 276.371 ms | max at: 245.511282 s
plasma-desktop:1753 | 223.251 ms | 1582 | avg: 4.220 ms | max: 299.354 ms | max at: 337.242542 s
kwin:1745 | 156.746 ms | 2879 | avg: 2.398 ms | max: 355.765 ms | max at: 337.242490 s
pulseaudio:1797 | 60.268 ms | 2573 | avg: 0.695 ms | max: 36.069 ms | max at: 292.318120 s
threaded-ml:3477 | 47.076 ms | 3878 | avg: 7.083 ms | max: 1898.940 ms | max at: 254.919367 s
perf:3437 | 28.525 ms | 4 | avg: 129.042 ms | max: 498.816 ms | max at: 336.102154 s

4.2.3
-----------------------------------------------------------------------------------------------------------------
Task | Runtime ms | Switches | Average delay ms | Maximum delay ms | Maximum delay at |
-----------------------------------------------------------------------------------------------------------------
oink:(8) | 741307.292 ms | 42325 | avg: 1.276 ms | max: 23.598 ms | max at: 192.459790 s
mplayer:(25) | 35296.804 ms | 35423 | avg: 1.715 ms | max: 71.972 ms | max at: 128.737783 s
Xorg:929 | 13257.917 ms | 21583 | avg: 0.091 ms | max: 27.983 ms | max at: 102.272376 s
testo:(9) | 2315.080 ms | 13213 | avg: 0.133 ms | max: 6.632 ms | max at: 201.422570 s
konsole:1747 | 938.939 ms | 1458 | avg: 0.096 ms | max: 15.006 ms | max at: 102.260294 s
kwin:1703 | 815.384 ms | 17376 | avg: 0.464 ms | max: 9.311 ms | max at: 119.026179 s
pulseaudio:1762 | 396.168 ms | 14338 | avg: 0.020 ms | max: 6.514 ms | max at: 115.928179 s
threaded-ml:3477 | 310.132 ms | 23966 | avg: 0.428 ms | max: 27.974 ms | max at: 134.100588 s
plasma-desktop:1711 | 239.232 ms | 1577 | avg: 0.048 ms | max: 7.072 ms | max at: 102.060279 s
perf:3434 | 65.705 ms | 2 | avg: 0.054 ms | max: 0.105 ms | max at: 102.011221 s

master, mplayer solo reference
-----------------------------------------------------------------------------------------------------------------
Task | Runtime ms | Switches | Average delay ms | Maximum delay ms | Maximum delay at |
-----------------------------------------------------------------------------------------------------------------
mplayer:(25) | 32171.732 ms | 18416 | avg: 0.012 ms | max: 4.405 ms | max at: 4911.226038 s
Xorg:948 | 14271.286 ms | 17396 | avg: 0.016 ms | max: 0.082 ms | max at: 4911.243020 s
testo:4121 | 3594.784 ms | 11607 | avg: 0.015 ms | max: 0.078 ms | max at: 4981.705240 s
kwin:1650 | 1209.387 ms | 17562 | avg: 0.012 ms | max: 1.612 ms | max at: 4911.245523 s
konsole:1728 | 967.914 ms | 1498 | avg: 0.007 ms | max: 0.048 ms | max at: 4997.903759 s
pulseaudio:1750 | 684.342 ms | 14460 | avg: 0.013 ms | max: 0.552 ms | max at: 4957.743502 s
threaded-ml:4153 | 641.893 ms | 15748 | avg: 0.016 ms | max: 2.201 ms | max at: 4923.928810 s
plasma-desktop:1658 | 150.068 ms | 569 | avg: 0.011 ms | max: 0.390 ms | max at: 4911.258650 s
perf:4126 | 43.854 ms | 3 | avg: 0.022 ms | max: 0.051 ms | max at: 4959.327694 s

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