Messages in this thread | | | Subject | Re: current_thread_info() vs task_thread_info(current) | From | Benjamin Herrenschmidt <> | Date | Mon, 18 Jul 2011 21:54:57 +1000 |
| |
On Mon, 2011-07-18 at 13:23 +0200, Peter Zijlstra wrote:
> So how are we going to solve this? Naively I'd think that > current_thread_info() is short for task_thread_info(current), and thus > the platforms for where this isn't true are broken. > > I mean, what use is the thread_info not of a thread? > > Comments?
Thomas just hit a bug in the platform code of said platform (powerpc heh ?) :-)
We do it right for hard IRQs and for some reason never did it right for softirqs.
The code is like this for the former:
static inline void handle_one_irq(unsigned int irq) {
.../...
call_handle_irq(irq, desc, irqtp, desc->handle_irq); current->thread.ksp_limit = saved_sp_limit; irqtp->task = NULL;
/* Set any flag that may have been set on the * alternate stack */ if (irqtp->flags) set_bits(irqtp->flags, &curtp->flags); }
So what we need, I suppose is to add those two last line to do_softirq_onstack() as well.
Now indeed i386 needs a similar treatment on both hard and soft irqs (along with getting rid of that stupid duplication of call_on_stack in there, I don't think it's worth making the code horrible like that to save one clobber and PeterZ reckons we can probably avoid it using always_inline anyways).
I'll let you guys sort i386 out tho, I'll look at fixing ppc tomorrow :-)
Cheers, Ben.
| |