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Subject: Re: [PATCH] Avoid moving tasks when a schedule can be made.
From: Steven Rostedt <rostedt@goodmis.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>,
       Peter Williams <pwil3058@bigpond.net.au>,
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Date: Wed, 01 Feb 2006 09:32:17 -0500
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On Wed, 2006-02-01 at 15:22 +0100, Ingo Molnar wrote:
> * Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> 
> > >rwsems/rwlocks are not an issue in -rt because they have different 
> > >semantics there - and thus readers cannot amass. I do think rwsems and 
> > >rwlocks have pretty nasty characteristics [non-latency ones] for the 
> > >mainline kernel's use too, but that's not being argued here ;)
> > 
> > But all I'm saying is that while there are equivalent magnitudes of 
> > interrupts off regions in mainline, there is little point introducing 
> > a hack like this to "solve" one of them.
> 
> nobody is arguing to have this hack included. Hacks are to be introduced 
> into the scheduler only over my cold dead body ;-) Steve only sent this 
> as an RFC thing, to raise the issue.

I'll confirm this. Even in my submission, I stated that this was
probably wrong, and wanted comments (thank you btw for commenting :).  I
just wanted to show where the problem was, and that the problem went
away with the "hack".

-- Steve