Date: Thu, 30 Aug 2007 14:09:39 +0400
From: Oleg Nesterov <oleg@tv-sign.ru>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Vitaly Mayatskikh <vmayatsk@redhat.com>, linux-kernel@vger.kernel.org,
       Ingo Molnar <mingo@elte.hu>, Pavel Emelianov <xemul@openvz.org>
Subject: Re: [PATCH 2.6.21] Return available first timeslice to the creator, not parent
Message-ID: <20070830100939.GA372@tv-sign.ru>
References: <m3fy21qx4p.fsf@dhcp-lab-143.englab.brq.redhat.com> <1188465056.6112.30.camel@twins> <20070830094931.GB316@tv-sign.ru> <1188467816.6112.36.camel@twins>
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On 08/30, Peter Zijlstra wrote:
>
> On Thu, 2007-08-30 at 13:49 +0400, Oleg Nesterov wrote:
> > 
> > sched_exit() was removed in 2.6.23-rc.
> > 
> > If you are going to re-introduce this logic, please don't do sched_exit()
> > from release_task(). It was done this way just because we can't access
> > ->parent after release_task(). But release_task() is called either too
> > early, or too late for timeslice accounting, depending on ->exit_signal == -1.
> > 
> > I'd suggest to do this in do_exit(), before the last schedule(). Without
> > write_unlock_irq() the code above needs a couple of rcu_read_lock()'s.
> > 
> > I am not sure Ingo will like this change though...
> 
> This is not intended as re-introduction of the feature, this stems from
> fixing this issue in older (read distro) kernels.

Ah, good, sorry for noise then.

In that case I don't think it makes sense to move sched_exit() to do_exit(),
of course. This doesn't look suitable for the -stable tree.

Oleg.

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