Re: Forward port of latest RT patch (2.6.21.5-rt20) to 2.6.22 available

Gregory Haskins
2007-07-12T16:27:10Z

On Thu, 2007-07-12 at 14:07 +0200, Ingo Molnar wrote:
> great! We had the upstream -rt port to .22 in the works too, it was just
> held up by the hpet breakage - which Thomas managed to fix earlier
> today. I've released the 2.6.22.1-rt1 patch to the usual place:
>
> http://redhat.com/~mingo/realtime-preempt/

Hi Ingo,
For the most part, it seems you guys have resolved most of the issues
that we ran into as well (e.g. early-flush-tlb, relocated die-notifier,
etc, come to mind). I found one patch that was missing that allows
debug configurations to build properly. Heres that patch:

--- linux-2.6.21.orig/kernel/latency_trace.c
+++ linux-2.6.21/kernel/latency_trace.c
@@ -24,6 +24,7 @@
#include <linux/utsrelease.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
+#include <asm/asm-offsets.h>
#include <asm/rtc.h>
#include <linux/stacktrace.h>

With this patch in place, I am able to build/boot both a 21.1-rt1 kernel
with a standard x86_64 PREEMPT_RT+SMP both with and without the usual
debug options, so that is great!

We did find a regression. I was mistaken earlier when I mentioned our
T60p laptops couldn't boot. It turns out that issue was resolved
somewhere along the way and our published patches based on 21.5-rt19 do
allow the laptop to boot event with acpi=on. With 22.1-rt1 the laptop
crashes unless acpi=off. Now that we have your queue we will bisect
this and post that fix as well.

Thanks!
-Greg