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Date: Fri, 21 Jan 2011 23:03:23 +0800
From: Yong Zhang <yong.zhang0@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>, samu.p.onkalo@nokia.com, mingo@elte.hu,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        tglx <tglx@linutronix.de>, Steven Rostedt <rostedt@goodmis.org>
Subject: Re: Bug in scheduler when using rt_mutex
Message-ID: <20110121150323.GC6051@zhy>
Reply-To: Yong Zhang <yong.zhang0@gmail.com>
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On Fri, Jan 21, 2011 at 02:40:58PM +0100, Peter Zijlstra wrote:
> On Fri, 2011-01-21 at 20:24 +0800, Yong Zhang wrote:
> > > Index: linux-2.6/kernel/sched.c
> > > ===================================================================
> > > --- linux-2.6.orig/kernel/sched.c
> > > +++ linux-2.6/kernel/sched.c
> > > @@ -2624,6 +2624,8 @@ void sched_fork(struct task_struct *p, i
> > >  
> > >       if (!rt_prio(p->prio))
> > >               p->sched_class = &fair_sched_class;
> > > +     else
> > > +             p->se.vruntime = 0;
> > 
> > This can be moved to __sched_fork() 
> 
> But we cannot do it unconditionally, we want to inherit the parent's
> ->vruntime when we're a fair task clone.

Doesn't task_fork_fair()(which is called after __sched_fork())
take the inherit job?

Am I missing something?

Thanks,
Yong