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From: Bruce Merry <bmerry@ska.ac.za>
To: linux-kernel@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
	Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: [PATCH v2] perf bench: fix order of arguments to memcpy_alloc_mem
Date: Thu, 15 Jan 2015 11:20:22 +0200	[thread overview]
Message-ID: <20150115092022.GA11292@kryton> (raw)

This was causing the destination instead of the source to be filled.
As a result, the source was typically all mapped to one zero page,
and hence very cacheable.

Signed-off-by: Bruce Merry <bmerry@ska.ac.za>
---
 tools/perf/bench/mem-memcpy.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/bench/mem-memcpy.c b/tools/perf/bench/mem-memcpy.c
index 6c14afe..db1d3a2 100644
--- a/tools/perf/bench/mem-memcpy.c
+++ b/tools/perf/bench/mem-memcpy.c
@@ -289,7 +289,7 @@ static u64 do_memcpy_cycle(const struct routine *r, size_t len, bool prefault)
 	memcpy_t fn = r->fn.memcpy;
 	int i;
 
-	memcpy_alloc_mem(&src, &dst, len);
+	memcpy_alloc_mem(&dst, &src, len);
 
 	if (prefault)
 		fn(dst, src, len);
@@ -312,7 +312,7 @@ static double do_memcpy_gettimeofday(const struct routine *r, size_t len,
 	void *src = NULL, *dst = NULL;
 	int i;
 
-	memcpy_alloc_mem(&src, &dst, len);
+	memcpy_alloc_mem(&dst, &src, len);
 
 	if (prefault)
 		fn(dst, src, len);
-- 
1.9.1



             reply	other threads:[~2015-01-15  9:20 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-15  9:20 Bruce Merry [this message]
2015-02-19  0:31 ` [PATCH v2] perf bench: fix order of arguments to memcpy_alloc_mem Ingo Molnar
2015-03-01 16:49 ` [tip:perf/urgent] perf bench: Fix " tip-bot for Bruce Merry

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