Commit e17fdaea authored Jan 15, 2015 by Bruce Merry Committed by Arnaldo Carvalho de Melo Feb 22, 2015

perf bench: Fix order of arguments to memcpy_alloc_mem

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>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150115092022.GA11292@kryton

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 2a6730c8

tools/perf/bench/mem-memcpy.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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);