From: Jan Beulich Date: Wed, 18 Jan 2012 13:28:13 +0000 (+0000) Subject: perf bench: Make "default" memcpy() selection actually use glibc's implementation X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=9ea811973d49a1df0be04ff6e4df449e4fca4fb5;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git perf bench: Make "default" memcpy() selection actually use glibc's implementation Since arch/x86/lib/memcpy_64.S implements not only __memcpy, but also memcpy, without further precautions this function will get chose by the static linker for resolving all references, and hence the "default" measurement didn't really measure anything else than the "x86-64-unrolled" one. Fix this by renaming (through the pre-processor) the conflicting symbol. On my Westmere system, the glibc variant turns out to require about 4% less instructions, but 15% more cycles for the default 1Mb block size measured. Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/4F16D6FD020000780006D72F@nat28.tlf.novell.com Signed-off-by: Jan Beulich Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/bench/mem-memcpy-x86-64-asm.S b/tools/perf/bench/mem-memcpy-x86-64-asm.S index a57b66e853c2..384b60788ab9 100644 --- a/tools/perf/bench/mem-memcpy-x86-64-asm.S +++ b/tools/perf/bench/mem-memcpy-x86-64-asm.S @@ -1,2 +1,2 @@ - +#define memcpy MEMCPY /* don't hide glibc's memcpy() */ #include "../../../arch/x86/lib/memcpy_64.S"