Hi Hitoshi,

On 2013/6/7 21:50, Hitoshi Mitake wrote:

> At Fri, 7 Jun 2013 09:26:58 +0800,
> Jianguo Wu wrote:
>>
>> Hi Hitoshi,
>>
>> Thanks for your reply! please see below.
>>
>> On 2013/6/6 21:54, Hitoshi Mitake wrote:
>>
>>> Hi Jianguo,
>>>
>>> On Wed, Jun 5, 2013 at 12:26 PM, Jianguo Wu <wujianguo@huawei.com> wrote:
>>>> Hi,
>>>> One more question, I wrote a memcpy test program, mostly the same as with perf bench memcpy.
>>>> But test result isn't consistent with perf bench when THP is off.
>>>>
>>>>         my program                              perf bench
>>>> THP:    3.628368 GB/Sec (with prefault)         3.672879 GB/Sec (with prefault)
>>>> NO-THP: 3.612743 GB/Sec (with prefault)         6.190187 GB/Sec (with prefault)
>>>>
>>>> Below is my code:
>>>>         src = calloc(1, len);
>>>>         dst = calloc(1, len);
>>>>
>>>>         if (prefault)
>>>>                 memcpy(dst, src, len);
>>>>         gettimeofday(&tv_start, NULL);
>>>>         memcpy(dst, src, len);
>>>>         gettimeofday(&tv_end, NULL);
>>>>
>>>>         timersub(&tv_end, &tv_start, &tv_diff);
>>>>         free(src);
>>>>         free(dst);
>>>>
>>>>         speed = (double)((double)len / timeval2double(&tv_diff));
>>>>         print_bps(speed);
>>>>
>>>> This is weird, is it possible that perf bench do some build optimize?
>>>>
>>>> Thansk,
>>>> Jianguo Wu.
>>>
>>> perf bench mem memcpy is build with -O6. This is the compile command
>>> line (you can get this with make V=1):
>>> gcc -o bench/mem-memcpy-x86-64-asm.o -c -fno-omit-frame-pointer -ggdb3
>>> -funwind-tables -Wall -Wextra -std=gnu99 -Werror -O6 .... # ommited
>>>
>>> Can I see your compile option for your test program and the actual
>>> command line executing perf bench mem memcpy?
>>>
>>
>> I just compiled my test program with gcc -o memcpy-test memcpy-test.c.
>> I tried to use the same compile option with perf bench mem memcpy, and
>> the test result showed no difference.
>>
>> My execute command line for perf bench mem memcpy:
>> #./perf bench mem memcpy -l 1gb -o
> 
> Thanks for your information. I have three more requests for
> reproducing the problem:
> 
> 1. the entire source code of your program

Please see the attachment.

> 2. your gcc version

4.3.4

> 3. your glibc version

glibc-2.11.1-0.17.4

Thanks,
Jianguo Wu

> 
> I should've requested it first, sorry :(
> 
> Thanks,
> Hitoshi
> 
> .
>