Thomas Gleixner wrote:
quoted text
> On Tue, 26 Aug 2008, Nick Piggin wrote:
> 
>> On Tuesday 26 August 2008 19:30, Ingo Molnar wrote:
>>> * Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>>>> So... no reply to this? I'm really wondering how it's OK to break
>>>> documented standards and previous Linux behaviour by default for
>>>> something that it is trivial to solve in userspace? [...]
>>> I disagree
>> Your arguments were along the line of:
>>
>> * It probably doesn't break anything (except we had somebody report
>>   that it breaks their app)
> 
> I'm a real-time oldtimer. An application which hogs the CPU for 9.9
> seconds with SCHED_FIFO priority is just broken. It's broken beyond
> all limits, whether POSIX allows to do that or Linux obeyed the
> request of the braindamaged application design.
> 

Well, I've been working on RT hardware (mostly) and software since 1977.
With all due respect, thats crapola. I for one have this requirement and
there is _no_ way around it in my world. In fact it's the kernel thats broke
by stealing precious usecs from me.

From my point of view, as an RT user, any kernel that supports SMP yet can't 
guarantee me %100 of even one _my_ processors is just a plainly broken kernel. 

quoted text
>> * If it does break something then they must be doing something stupid
>>   (I refuted that because there are several legitimate ways to use rt
>>   scheduling that is broken by this)
>>
>> * We have many other APIs and tools that don't conform to posix (why
>>   is that a reason to break this one?)
> 
> Simply because we use common sense instead of following every single
> POSIX brainfart by the letter.
> 
>> * We should break the API to cater for stupid users and distros who
>>   create local DoS and/or lock up their boxes (except this is trivial
>>   to solve by setting sysctls or having a watchdog or using sysrq)
> 
> For the vast majority of users and RT developers a sane default of
> sanity measures is useful and sensible. 
> 
> If someone wants to shoot himself in the foot then it's not an
> unreasonable request that he needs to disable the safety guards before
> pulling the trigger.
> 

Again that is also crapola. If i want to shoot myself in the foot, it's
none of your concern. I know perfectly well what will happen when 
I pull the trigger. 

My 2 cents
Regards
Mark
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