Re: [RFC PATCH 11/15] x86: Nohz task support

[Frederic Weisbecker]

On Tue, Dec 21, 2010 at 09:05:29AM +0100, Peter Zijlstra wrote:
> On Tue, 2010-12-21 at 02:30 +0100, Frederic Weisbecker wrote:
> > On Mon, Dec 20, 2010 at 05:23:19PM +0100, Peter Zijlstra wrote:
> > > On Mon, 2010-12-20 at 16:24 +0100, Frederic Weisbecker wrote:
> > > > 
> > > > Implement the thread flag, syscalls and exception hooks for
> > > > nohz task support.
> > > > 
> > > 
> > > I saw:
> > >  - syscall
> > >  - do_int3
> > >  - do_debug (int1)
> > >  - #PF
> > > 
> > > So where's all other interrupts?
> > 
> > No need to handle them.
> > 
> > We have:
> > 
> > rcu_irq_enter() rcu_irq_exit() rcu_nmi_enter() rcu_nmi_exit()
> > and they already act as pauses into extended quiescent states, which
> > is enough for our needs.
> 
> Oh, and RCU is the only thing you need to worry about is it?

wrt userspace/kernelspace switches yes, for now. But perhaps I'll discover
more reasons to hook into that boundary.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/