Re: [revert] mysql+oltp regression

[Ingo Molnar <mingo@elte.hu>]

* Gregory Haskins <ghaskins@novell.com> wrote:

> Gregory Haskins wrote:
>> Ingo Molnar wrote:
>>> * Gregory Haskins <ghaskins@novell.com> wrote:
>>>
>>>  
>>>>>> Speaking of this: Another patch I submitted to you Ingo (had to 
>>>>>> do with updating the load_weight inside task_setprio) seems to 
>>>>>> also have this phenomenon: e.g. its technically correct but 
>>>>>> further testing has revealed negative repercussions elsewhere.  
>>>>>> So please ignore that patch (or revert if you already pulled 
>>>>>> in, but I don't think you have).  Ill try to look into this 
>>>>>> issue as well.
>>>>>>         
>>>>> ok, under which thread/subject is that? Not queued in tip/sched/* 
>>>>> yet, correct?
>>>>>         
>>>> Here is the original thread:
>>>>
>>>> http://lkml.org/lkml/2008/7/3/416
>>>>
>>>> I do not believe you have queued it anywhere (public anyway) yet.
>>>>
>>>> Note I have already invalidated 1/2, and now I am retracting 2/2 as 
>>>> well.  (1/2 is actually a bogus patch, 2/2 is "technically correct" 
>>>> but causes ripples in the load balancer that need to be sorted out  
>>>> first.
>>>>     
>>>
>>> ok, thanks. I'm curious, what are those ripple effects? Stability or  
>>> performance?
>>>   
>>
>> Performance.  I found it while working on my pi series (which fyi I  
>> should have a v2 refresh for soon, probably today...i am hoping to get  
>> some review feedback from you on that as well, time permitting of  
>> course ;).
>>
>> Basically the behavior I was observing was that kernel builds via  
>> distcc would cluster all the cc1 jobs on a single core.  At first I  
>> thought my pi-series was screwed up, but then I realized I had applied  
>> the patch referenced above earlier in my development tree, and  
>> removing it allowed pi to work fine.
>>
>> I found the problem with in once boot cycle with ftrace (thanks Steve!).
>
> Hmm..Im not sure what went wrong between brain and hand above, but of 
> course I meant to say ".. within one boot cycle ..", not "with in 
> once".  Heh.

my second reading of that sentence auto-corrected it to your intented 
version ;-)

	Ingo