From: Anton Blanchard <anton@samba.org>
Date: Thu, 18 Sep 2014 23:40:21 +0000 (+1000)
Subject: powerpc: Enable DCACHE_WORD_ACCESS on ppc64le
X-Git-Tag: omap-for-v3.19/prcm-cleanup~114^2~58
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a75c380c7129c432f8ac9d42ebc170e5f7d9d31e;p=pandora-kernel.git

powerpc: Enable DCACHE_WORD_ACCESS on ppc64le

Enable on DCACHE_WORD_ACCESS on ppc64le. It should work on
ppc64 and ppc32 but we need to do some testing first.

A somewhat reasonable testcase used to show the performance
improvement - a repeated stat of a 33 byte filename that
doesn't exist:

 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>

 #define ITERATIONS 10000000

 #define PATH "123456781234567812345678123456781"

 int main(void)
 {
 	unsigned long i;
 	struct stat buf;

 	for (i = 0; i < ITERATIONS; i++)
 		stat(PATH, &buf);

 	return 0;
 }

runs 27% faster on POWER8.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---

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