x86: apic: Cleanup and simplify setup_local_APIC()

Browse source

setup_local_APIC() is used to setup local APIC early during CPU
initialization and already assumes that preemption is disabled on
entry. However, The function unnecessarily disables and enables
preemption and uses smp_processor_id() multiple times in and out of
the nested preemption disabled section. This gives the wrong
impression that the function might be able to handle being called with
preemption enabled and/or migrated to another processor in the middle.

Make it clear that the function is always called with preemption
disabled, drop the confusing preemption disable block and call
smp_processor_id() once at the beginning of the function.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: brgerst@gmail.com
LKML-Reference: <4D00B3B9.7060702@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

...

This commit is contained in:

Tejun Heo 2010-12-09 11:47:21 +01:00 • committed by Thomas Gleixner

parent 0e3fa13f4e

commit 0aa002fe60

1 changed files with 9 additions and 12 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

21

arch/x86/kernel/apic/apic.c

View file