Re: [PATCH] powerpc/irq: Run softirqs off the top of the irq stack

2013-09-23 Thread Benjamin Herrenschmidt
On Mon, 2013-09-23 at 09:47 -0700, Linus Torvalds wrote: > On Sun, Sep 22, 2013 at 9:35 PM, Benjamin Herrenschmidt > wrote: > > > > This is the "band aid" discussed so far for the stack overflow > > problem for powerpc. > > I don't think it's a "band-aid" in any way, except perhaps in the > sense

Re: [PATCH] powerpc/irq: Run softirqs off the top of the irq stack

2013-09-23 Thread Linus Torvalds
On Sun, Sep 22, 2013 at 9:35 PM, Benjamin Herrenschmidt wrote: > > This is the "band aid" discussed so far for the stack overflow > problem for powerpc. I don't think it's a "band-aid" in any way, except perhaps in the sense that there are certainly other things we can also do in this series (ie

Re: [PATCH] powerpc/irq: Run softirqs off the top of the irq stack

2013-09-23 Thread Benjamin Herrenschmidt
On Mon, 2013-09-23 at 17:56 +1000, Stephen Rothwell wrote: > Hi Ben, > > On Mon, 23 Sep 2013 14:35:58 +1000 Benjamin Herrenschmidt > wrote: > > > > diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c > > index c69440c..0c9646f 100644 > > --- a/arch/powerpc/kernel/irq.c > > +++ b/a

Re: [PATCH] powerpc/irq: Run softirqs off the top of the irq stack

2013-09-23 Thread Stephen Rothwell
Hi Ben, On Mon, 23 Sep 2013 14:35:58 +1000 Benjamin Herrenschmidt wrote: > > diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c > index c69440c..0c9646f 100644 > --- a/arch/powerpc/kernel/irq.c > +++ b/arch/powerpc/kernel/irq.c > @@ -443,46 +443,7 @@ void migrate_irqs(void) > >

[PATCH] powerpc/irq: Run softirqs off the top of the irq stack

2013-09-22 Thread Benjamin Herrenschmidt
Nowadays, irq_exit() calls __do_softirq() pretty much directly instead of calling do_softirq() which switches to the decicated softirq stack. This has lead to observed stack overflows on powerpc since we call irq_enter() and irq_exit() outside of the scope that switches to the irq stack. This fix