From: James Hogan <james.hogan@imgtec.com>
Date: Fri, 28 Jun 2013 14:03:05 +0000 (+0100)
Subject: metag: smp: don't spin waiting for CPU to start
X-Git-Tag: v3.11-rc1~79^2~3
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9649814432faa9016952895684120942da0d8481;p=pandora-kernel.git

metag: smp: don't spin waiting for CPU to start

Use a completion to block until a secondary CPU has started up, like ARM
do, instead of a loop of udelays.

On Meta, SMP is really SMT, with each "CPU" being a different hardware
thread on the same Meta processor core, so as well as being more
efficient and latency friendly, using a completion prevents the bogomips
of the secondary CPU from being drastically skewed every time by the
execution of the tight in-cache udelay loop on the other CPU.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
---

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