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authorJan Beulich <JBeulich@suse.com>2012-01-18 13:28:56 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2012-01-24 19:51:01 -0200
commit800eb01484b3ca1eaf4eb5186df13fb24de2db19 (patch)
tree689b76d267371bbb5a614cefccaa0bea96187134
parent9ea811973d49a1df0be04ff6e4df449e4fca4fb5 (diff)
downloadlwn-800eb01484b3ca1eaf4eb5186df13fb24de2db19.tar.gz
lwn-800eb01484b3ca1eaf4eb5186df13fb24de2db19.zip
perf bench: Also allow measuring alternative memcpy implementations
Intended to be able to support the current selection of the preferred memcpy() implementation, this patch adds the ability to also measure the two alternative implementations, again by way of using some pre-processsor replacement. While on my Westmere system this proves that the movsb based variant is worse than the movsq based one (since the ERMS feature isn't there), it also shows that here for the default as well as small sizes the unrolled variant outperforms the movsq one. Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F16D728020000780006D732@nat28.tlf.novell.com Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r--tools/perf/bench/mem-memcpy-x86-64-asm-def.h8
-rw-r--r--tools/perf/bench/mem-memcpy-x86-64-asm.S4
2 files changed, 12 insertions, 0 deletions
diff --git a/tools/perf/bench/mem-memcpy-x86-64-asm-def.h b/tools/perf/bench/mem-memcpy-x86-64-asm-def.h
index d588b87696fc..d66ab799b35f 100644
--- a/tools/perf/bench/mem-memcpy-x86-64-asm-def.h
+++ b/tools/perf/bench/mem-memcpy-x86-64-asm-def.h
@@ -2,3 +2,11 @@
MEMCPY_FN(__memcpy,
"x86-64-unrolled",
"unrolled memcpy() in arch/x86/lib/memcpy_64.S")
+
+MEMCPY_FN(memcpy_c,
+ "x86-64-movsq",
+ "movsq-based memcpy() in arch/x86/lib/memcpy_64.S")
+
+MEMCPY_FN(memcpy_c_e,
+ "x86-64-movsb",
+ "movsb-based memcpy() in arch/x86/lib/memcpy_64.S")
diff --git a/tools/perf/bench/mem-memcpy-x86-64-asm.S b/tools/perf/bench/mem-memcpy-x86-64-asm.S
index 384b60788ab9..a20780bd0771 100644
--- a/tools/perf/bench/mem-memcpy-x86-64-asm.S
+++ b/tools/perf/bench/mem-memcpy-x86-64-asm.S
@@ -1,2 +1,6 @@
#define memcpy MEMCPY /* don't hide glibc's memcpy() */
+#define altinstr_replacement text
+#define globl p2align 4; .globl
+#define Lmemcpy_c globl memcpy_c; memcpy_c
+#define Lmemcpy_c_e globl memcpy_c_e; memcpy_c_e
#include "../../../arch/x86/lib/memcpy_64.S"