Messages in this thread | | | Date | Sat, 30 Oct 2010 21:23:57 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 2/2] perf bench: add x86-64 specific benchmarks to perf bench mem memcpy |
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* Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> wrote:
> This patch adds new file: mem-memcpy-x86-64-asm.S > for x86-64 specific memcpy() benchmarking. > Added new benchmarks are, > x86-64-rep: memcpy() implemented with rep instruction > x86-64-unrolled: unrolled memcpy() > > Original idea of including the source files of kernel > for benchmarking is suggested by Ingo Molnar. > This is more effective than write-once programs for quantitative > evaluation of in-kernel, little and leaf functions called high frequently. > Because perf bench is in kernel source tree and executing it > on various hardwares, especially new model CPUs, is easy. > > This way can also be used for other functions of kernel e.g. checksum functions. > > Example of usage on Core i3 M330: > > | % ./perf bench mem memcpy -l 500MB > | # Running mem/memcpy benchmark... > | # Copying 500MB Bytes from 0x7f911f94c010 to 0x7f913ed4d010 ... > | > | 578.732506 MB/Sec > | % ./perf bench mem memcpy -l 500MB -r x86-64-rep > | # Running mem/memcpy benchmark... > | # Copying 500MB Bytes from 0x7fb4b6fe4010 to 0x7fb4d63e5010 ... > | > | 738.184980 MB/Sec > | % ./perf bench mem memcpy -l 500MB -r x86-64-unrolled > | # Running mem/memcpy benchmark... > | # Copying 500MB Bytes from 0x7f6f2e668010 to 0x7f6f4da69010 ... > | > | 767.483269 MB/Sec > > This shows clearly that unrolled memcpy() is efficient > than rep version and glibc's one :)
Hey, really cool output :-)
Might also make sense to measure Ma Ling's patched version?
> # checkpatch.pl warns about two externs in bench/mem-memcpy.c > # added by this patch. But I think it is no problem.
You should put these:
+#ifdef ARCH_X86_64 +extern void *memcpy_x86_64_unrolled(void *to, const void *from, size_t len); +extern void *memcpy_x86_64_rep(void *to, const void *from, size_t len); +#endif
into a .h file - a new one if needed.
That will make both checkpatch and me happier ;-)
Thanks,
Ingo
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