Kernel Preemption patch

[Todd Poynor]

At 07:56 AM 2/24/2003, brian.auld at adic.com wrote:

> However, I noticed that your 'preempt_enable' at the bottom of the
> exerp has
> been changed from 'preempt_enable' as in the RML patch, to
> 'preempt_enable_no_reshed'. What's the reason for this inconsistency?

The preempt_enable_no_reshed avoids a kernel stack overflow seen in
certain cases of heavy preemption, where each nested call to reschedule
on preemption is interrupted and again requests a preemption.  The
proper place to check for another preemption is at the top-level
interrupt/exception handler, so that we iterate and not recurse.

Oops, MontaVista needs to contribute this bug fix back to RML's public
patch, I'll put it on my list.


--
Todd


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/