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
next 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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