From: Jeremy Kerr <jk@ozlabs.org>
Date: Wed, 19 Sep 2007 04:38:12 +0000 (+1000)
Subject: [POWERPC] cell: Unify spufs syscall path
X-Git-Tag: v2.6.24-rc1~1450^2~226
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=98f06978ffebbec16abdea58489f217229580859;p=pandora-kernel.git

[POWERPC] cell: Unify spufs syscall path

At present, a built-in spufs will not use the spufs_calls callbacks, but
directly call sys_spu_create.  This saves us an indirect branch, but
means we have duplicated functions - one for CONFIG_SPU_FS=y and one for
=m.

This change unifies the spufs syscall path, and provides access to the
spufs_calls structure through a get/put pair.  At present, the only user
of the spufs_calls structure is spu_syscalls.c, but this will facilitate
adding the coredump calls later.

Everyone likes numbers, right?  Here's a before/after comparison with
CONFIG_SPU_FS=y, doing spu_create(); close(); 64k times.

Before:
	[jk@cell ~]$ time ./spu_create
	performing 65536 spu_create calls

	real    0m24.075s
	user    0m0.146s
	sys     0m23.925s

After:
	[jk@cell ~]$ time ./spu_create
	performing 65536 spu_create calls

	real    0m24.777s
	user    0m0.141s
	sys     0m24.631s

So, we're adding around 11us per syscall, at the benefit of having
only one syscall path.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---

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