Re: [REPORT] cfs-v4 vs sd-0.44


* Willy Tarreau <w@xxxxxx> wrote:

I promised to perform some tests on your code. I'm short in time right
now, but I observed behaviours that should be commented on.

thanks for the feedback!

3) CFS-v4

Feels even better, mouse movements are very smooth even under high
load. I noticed that X gets reniced to -19 with this scheduler. I've
not looked at the code yet but this looked suspicious to me. I've
reniced it to 0 and it did not change any behaviour. Still very
good. The 64 ocbench share equal CPU time and show exact same
progress after 2000 iterations. The CPU load is more smoothly spread
according to vmstat, and there's no idle (see below). BUT I now
think it was wrong to let new processes start with no timeslice at
all, because it can take tens of seconds to start a new process when
only 64 ocbench are there. [...]

ok, i'll modify that portion and add back the 50%/50% parent/child CPU
time sharing approach again. (which CFS had in -v1) That should not
change the rest of your test and should improve the task startup
characteristics.

Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/