Re: [PATCH] Prevent nested interrupts when the IRQ stack is near overflowing v2

Andi Kleen
2010-03-25T18:44:41Z

On Thu, Mar 25, 2010 at 07:23:58PM +0100, Peter Zijlstra wrote:
> On Thu, 2010-03-25 at 19:21 +0100, Peter Zijlstra wrote:
> > On Thu, 2010-03-25 at 11:01 -0700, Linus Torvalds wrote:
> > > Are there any cases around
> > > that still have busy-loop delays based on real-time in their irq handlers?
> > > I simply don't know.
> >
> > I recently found a few in drivers/net/ there's all kinds of funny stuff
> > in there.. not sure how common the matching hardware is though.
> >
> > One thing we could do is instrument jiffies to yell when its used from
> > hardirq context and fix up these things.
>
> Also, Arjan mentioned he wanted to sweep the kernel for jiffies users
> and convert them to timer interfaces..

% linux-2.6> gid jiffies | wc -l
7569

Good luck.

-Andi

--
ak@linux.intel.com -- Speaking for myself only.