Subject: timer irq setup

From: Thomas Koeller <[email-masked]>
Date: Mon, 17 Dec 2007 11:35:22 +0100

In arch/mips/kernel/traps.c, per_cpu_trap_init() contains
code to set up the global cp0_compare_irq variable. Does
this make sense? I'd say that either the irq setup should
be moved to trap_init(), or cp0_compare_irq should be
changed to a per-cpu variable, depending on what the original
intention was.

tk
-- 
Thomas Koeller
thomas at koeller dot dyndns dot org

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From: Ralf Baechle <[email-masked]>
Date: Tue, 18 Dec 2007 11:48:34 +0100

> changed to a per-cpu variable, depending on what the original

Technically it would be legal to route the timer interrupt to a different
interrupt for each of possibly multiple processors, that's why it's done
in per_cpu_trap_init().

Obviously the rest of the code isn't quite there and also to best of my
knowledge all actual implementations use the same interrupt across all
cores.  So something like a global variable and a paranoia check in
per_cpu_trap_init() to ensure all CPUs really use the same interrupt
would seem reasonable.

  Ralf