Re: 2.6.21-rc3-mm1 RSDL results

Mark Lord
2007-03-13T22:06:39Z

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