Re: [dpdk-dev] rte_memcpy optimization patch to dpdk ver 1.7

[Vithal S Mohare <vmohare@arubanetworks.com>]

Ok, crash, as expected.   So, now dpdk mandates either AVX2 or SSSE2 supported CPUs.   OR applications needs to handle it run-time.

Thanks,
-Vithal

-----Original Message-----
From: Neil Horman [mailto:nhorman@tuxdriver.com] 
Sent: Tuesday, February 17, 2015 6:32 PM
To: Vithal S Mohare
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] rte_memcpy optimization patch to dpdk ver 1.7

On Tue, Feb 17, 2015 at 08:39:22AM +0000, Vithal S Mohare wrote:
> Hi,
> 
> I am trying to use rte_memcpy optimization patch along with dpdk version 1.7.  With the patch, while dpdk itself is compiled, applications failed with below error:
> -------------------------------
> include/rte_memcpy.h:629:2: error: implicit declaration of function 
> '_mm_alignr_epi8' [-Werror=implicit-function-declaration]
> /home/vithals/adu_src/build/x-men_dev/Default/shumway/infra/dpdk/shumway_obj/lib/../include/rte_memcpy.h:629:2: error: incompatible type for argument 2 of '_mm_storeu_si128'
> -------------------------------
> 
> After including -mssse3 flags, compilation (cross compiled for a x86 linux based platform) went through.  Now the question is, when this binary is loaded on system that doesn't support SSSE3 instruction set (but just sse2 etc), what would be the behavior?
> 
A crash.  You'll attempt to send an unknown binary instruction into the execution pipeline and the processor will fault.

Neil