Re: 2.6.21-rc3-mm1 RSDL results

From: Mark Lord
Date: Tue Mar 13 2007 - 18:06:53 EST


Con Kolivas wrote:
On Wednesday 14 March 2007 05:21, Mark Lord wrote:
Con Kolivas wrote:
Can you try the new version of RSDL. Assuming it doesn't oops on you it
has some accounting bugfixes which may have been biting you.
Retesting today with 2.6.21-rc3-git7 + 2.6.21-rc3-sched-rsdl-0.30.patch.

Still not pleasant to use the GUI with a kernel build (-j1 or -j2)
happening unless the build is manually "nice'd".

Also, accounting looks weird in top(1).

With a 100% busy machine, top will show something like this :
top - 14:20:11 up 10:22, 1 user, load average: 2.65, 2.80, 2.18
Tasks: 134 total, 4 running, 128 sleeping, 0 stopped, 2 zombie
Cpu(s): 68.7% us, 6.7% sy, 24.7% ni, 0.0% id, 0.0% wa, 0.0% hi, 0.0%
si Mem: 2076964k total, 2002560k used, 74404k free, 148924k
buffers Swap: 2409740k total, 244k used, 2409496k free, 1448876k
cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1824 root 36 10 11748 7244 1936 R 4.0 0.3 0:00.12 cc1
1845 root 31 0 8080 5272 1412 R 1.7 0.3 0:00.05 cc1
4139 root 20 0 176m 35m 6860 S 1.3 1.7 18:59.35 Xorg
29381 root 20 0 33712 16m 12m R 1.0 0.8 0:27.24 konsole
3 root 20 0 0 0 0 S 0.3 0.0 0:00.49 events/0
1529 root 20 0 2556 1460 752 S 0.3 0.1 0:00.05 make
14623 root 20 0 2200 1144 860 R 0.3 0.1 0:00.89 top
1 root 20 0 1568 532 464 S 0.0 0.0 0:00.22 init
2 root 39 19 0 0 0 S 0.0 0.0 0:00.01 ksoftirqd/0
4 root 20 0 0 0 0 S 0.0 0.0 0:00.00 khelper
5 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthread
Mmm.. I wonder where all of that 100% CPU went to.. the busiest tasks
are only showing up as 4.0% and 1.7% (when in fact they are using near
100%).

Nothing ever looks like it stays running for very long. That would be enough to account for this sort of top picture.

Sorry, I just don't buy that one. This was a 2-second sampling interval in top.
top(1) is a program that has to work, so if this scheduler breaks it like this,
then we need to understand and fix top(1) or the scheduler.

What HZ are you running? Do you usually run two makes at different nice levels?

This was HZ=1000, with NO_HZ. And, no, not normally different nice levels.
Here I was just trying to keep the machine usable while building a couple of things.

Keep at it. Someday this might be good enough for mainline,
but right now the stock scheduler beats it for my desktop (notebook) loads.

Cheers
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