Re: [PATCH v3] mempool: replace c memcpy code semantics with optimized rte_memcpy

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 7/5/2016 2:13 PM, Jerin Jacob wrote:
> On Tue, Jul 05, 2016 at 07:32:46PM +0800, Yuanhan Liu wrote:
>> On Tue, Jul 05, 2016 at 09:43:03AM +0100, Ferruh Yigit wrote:
>>> On 6/30/2016 6:28 PM, Thomas Monjalon wrote:
>>>> 2016-06-30 17:46, Jerin Jacob:
>>>>> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
>>>>> Acked-by: Olivier Matz <olivier.matz@6wind.com>
>>>>
>>>> Applied, thanks
>>>>
>>>
>>> Hi Jerin,
>>>
>>> This commit cause a compilation error on target i686-native-linuxapp-gcc
>>> with gcc6.
>>
>> Besides that, I'm more curious to know have you actually seen any
>> performance boost?
> 
> let me first address your curiosity,
> http://dpdk.org/dev/patchwork/patch/12993/( check the second comment)
> http://dpdk.org/ml/archives/dev/2016-June/042701.html
> 
> Ferruh,

Hi Jerin,

> 
> I have tested on a x86 machine with gcc 6.1. I could n't see any issues
> with i686-native-linuxapp-gcc target
Thanks for investigating the issue.

> 
> Steps following to create gcc 6.1 toolchain
> https://sahas.ra.naman.ms/2016/05/31/building-gcc6-1-on-fedora-23/
> (removed --disable-multilib to have support for -m32)
> 
> ➜ [dpdk-master] $ gcc -v
> Using built-in specs.
> COLLECT_GCC=gcc
> COLLECT_LTO_WRAPPER=/opt/gcc-6.1.0/libexec/gcc/x86_64-pc-linux-gnu/6.1.0/lto-wrapper
> Target: x86_64-pc-linux-gnu
> Configured with: ../gcc-6.1.0/configure --prefix=/opt/gcc-6.1.0
> --enable-languages=c,c++ --enable-libmudflap --with-system-zlib
> Thread model: posix
> gcc version 6.1.0 (GCC)
I am using Fedora24, which has gcc6 (6.1.1) as default.

> 
> More over this issue seems like an issue from x86 rte_memcpy implementation.
You are right. But i686 compilation starts failing with this commit.
And reverting this commit in the current HEAD solves the compilation
problem.
I am not really clear about reason of the compilation error.

Thanks,
ferruh