Re: More ULE bugs fixed.

Jeff Roberson wrote:
> On Thu, 16 Oct 2003, Eirik Oeverby wrote:
> 
> 
>>Jeff Roberson wrote:
>>
>>>On Wed, 15 Oct 2003, Eirik Oeverby wrote:
>>>
>>>
>>>
>>>>Eirik Oeverby wrote:
>>>>
>>>>
>>>>>Jeff Roberson wrote:
>>>>>
>>>>>
>>>>>
>>>>>>I fixed two bugs that were exposed due to more of the kernel running
>>>>>>outside of Giant.  ULE had some issues with priority propagation that
>>>>>>stopped it from working very well.
>>>>>>
>>>>>>Things should be much improved.  Feedback, as always, is welcome.  I'd
>>>>>>like to look into making this the default scheduler for 5.2 if things
>>>>>>start looking up.  I hope that scares you all into using it more. :-)
>>>>>
>>>>>
>>>>>Hi..
>>>>>Just tested, so far it seems good. System CPU load is floored (near 0),
>>>>>system is very responsive, no mouse sluggishness or random
>>>>>mouse/keyboard input.
>>>>>Doing a make -j 20 buildworld now (on my 1ghz p3 thinkpad ;), and
>>>>>running some SQLServer stuff in VMWare. We'll see how it fares.
>>>>
>>>>Hi, just a followup message.
>>>>I'm now running the buildworld mentioned above, and the system is pretty
>>>>much unusable. It exhibits the same symptoms as I have mentioned before,
>>>>mouse jumpiness, bogus mouse input (movement, clicks), and the system is
>>>>generally very jerky and unresponsive. This is particularily evident
>>>>when doing things like webpage loading/browsing/rendering, but it's
>>>>noticeable all the time, no matter what I am doing. As an example, the
>>>>last sentence I wote without seeing a single character on screen before
>>>>I was finsihed writing it, and it appeared with a lot more typos than I
>>>>usually make ;)
>>>>
>>>>I'm running *without* invariants and witness right now, i.e. a kernel
>>>>100% equal to the SCHED_4BSD kernel.
>>>
>>>
>>>Can you confirm the revision of your sys/kern/sched_ule.c file?  How does
>>>SCHED_4BSD respond in this same test?
>>
>>Yes I can. From file:
>>__FBSDID("$FreeBSD: src/sys/kern/sched_ule.c,v 1.59 2003/10/15 07:47:06
>>jeff Exp $");
>>I am running SCHED_4BSD now, with a make -j 20 buildworld running, and I
>>do not experience any of the problems. Keyboard and mouse input is
>>smooth, and though apps run slightly slower due to the massive load on
>>the system, there is none of the jerkiness I have seen before.
>>
>>Anything else I can do to help?
> 
> 
> Yup, try again. :-)  I found another bug and tuned some parameters of the
> scheduler.  The bug was introduced after I did my paper for BSDCon and so
> I never ran into it when I was doing serious stress testing.
> 
> Hopefully this will be a huge improvement.  I did a make -j16 buildworld
> and used mozilla while in kde2.  It was fine unless I tried to scroll
> around rapidly in a page full of several megabyte images for many minutes.

It is. Still not perfect, but now it's somewhere around the 4BSD mark I 
would say. Think about 'make buildworld' is that it doesn't get real 
tough before it hits some of the larger directories, like the crypto 
stuff etc., where there are many .c files in one dir - before it gets 
that far, there are at most 2 or 3 cc1 processes going concurrently.
As soon as I get 10-20 of them, things start getting sluggish, but I 
suppose it's hard to avoid that. What disturbs me somewhat, though, is 
that I get some of this sluggishness (and other symptoms i've mentioned 
before) even when i'm running 'nice -n 20 make -j 20 buildworld' .. 
meaning the cc1 processes and all that are running (very) nice. The fact 
that I still have issues even when doing that, would lead me to think 
the problem is somewhere else than in the scheduler..
Now I can't say I'm completely sure if this is also the case with 4BSD - 
I only tested the nice stuff after the last reboot.

But all in all, things are better now than yesterday morning. Kudos!

/Eirik