Re: [dpdk-users] Segmentation fault with -msse3

["Das, Surajit" <Surajit.Das@commscope.com>]

Hi Nicolas,

Looks like the CPU you are running on does not have the instruction ssse3.
To check the list of flags available of your cpu, you can run:
lscpu | grep Flags
You will find that in the list of flags, ssse3 is not available on your cpu.

You can compile and run your app with the flag removed without functional issues.
Only difference will be that a bunch of instructions that could have been done faster in CPU hardware using ssse3, will now be done in software.

Regards,
Surajit

From: users <users-bounces@dpdk.org> On Behalf Of nicolas.neel@allentis.eu
Sent: Thursday, March 4, 2021 10:27 PM
To: users@dpdk.org
Subject: [dpdk-users] Segmentation fault with -msse3

Hello dpdk users, I'm a newbie to dpdk and I try to get the list of the rss hash functions for a given port with the following code : static uint64_t get_rss_function(int port_id){ int ret; struct rte
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Hello dpdk users,





I'm a newbie to dpdk and I try to get the list of the rss hash functions for

a given port with the following code :





static uint64_t get_rss_function(int port_id){



                int ret;



                struct rte_eth_rss_conf rss_conf;





                ret = rte_eth_dev_rss_hash_conf_get(port_id,&rss_conf);



                if(ret < 0){



                               printf("No supported rss\n");



                               return 0;



                }



                return rss_conf.rss_hf;



}





I use dpdk version 20.11 and my code is compiled with the following flags (I

'm following the tips of the doc) :



CXXFLAGS += -mssse3 -mfma -mcx16 -msse4.1 -msse4.2 -mpopcnt -mavx -mavx2

-DALLOW_EXPERIMENTAL_API





I have a segmentation fault calling ret =

rte_eth_dev_rss_hash_conf_get(port_id,&rss_conf) ; and the coredump tell an

issue with __memcpy_ssse3().





If I remove the -mssse3 I don't have the crash.





Can you help me to identify the reason of the segmentation fault and tell me

if I can easily remove the < -mssse3 > flag ?





(Sorry for my english)



Regards



Nicolas