perftest: support set flow_label list val in GRH with RR method

[changchengx]

For different QP, it may need to set different flow_label. Extend the flow_label option to support list val configuration and keep compatibility.

[changchengx]

extend #224

[changchengx]

@HassanKhadour FYI

[sshaulnv]

@changchengx, can you please rebase?

[changchengx]

@sshaulnv Done

[changchengx]

@sshaulnv @HassanKhadour ping

[sshaulnv]

@changchengx thanks for your contribution, the PR is under review

[sshaulnv]

Hi @changchengx ,
im getting the following errors when trying to compile:

 src/perftest_parameters.c: In function ‘parser’:
src/perftest_parameters.c:2958:10: warning: implicit declaration of function ‘parse_flow_label_from_str’; did you mean ‘parse_ethertype_from_str’? [-Wimplicit-function-declaration]
      if (parse_flow_label_from_str(user_param, optarg)) {
          ^~~~~~~~~~~~~~~~~~~~~~~~~
          parse_ethertype_from_str
src/perftest_parameters.c: At top level:
src/perftest_parameters.c:3356:12: error: static declaration of ‘parse_flow_label_from_str’ follows non-static declaration
 static int parse_flow_label_from_str(struct perftest_parameters *user_param, char *flow_label_str)
            ^~~~~~~~~~~~~~~~~~~~~~~~~
src/perftest_parameters.c:2958:10: note: previous implicit declaration of ‘parse_flow_label_from_str’ was here
      if (parse_flow_label_from_str(user_param, optarg)) {
          ^~~~~~~~~~~~~~~~~~~~~~~~~
src/perftest_parameters.c:3356:12: warning: ‘parse_flow_label_from_str’ defined but not used [-Wunused-function]
 static int parse_flow_label_from_str(struct perftest_parameters *user_param, char *flow_label_str)
            ^~~~~~~~~~~~~~~~~~~~~~~~~

please fix it, and also update man page.

Thanks

[changchengx]

@sshaulnv Thanks for your check. I've updated the commit according to your feedback and requirement. If you still hit some problem, please let me know the build environment: OS version & gcc version

[sshaulnv]

in which scenario this will be true?

[changchengx]

@sshaulnv Good catch, it seems that's dead code. I'll remove this if-condition and feedback later.

[changchengx]

@sshaulnv This scenario is to deal with the case that user config the command option --flow_label=xxxx for more than one time. This is rare case.

[sshaulnv]

the app checks for duplicate arguments on the 'parser' function, and if it will encounter more than one appearance of 'flow_label' it will produce:

Duplicated argument: flow_label 
 Parser function exited with Error

please remove the dead code.
beside this, everything looks great and we can merge it.

[changchengx]

@sshaulnv I've removed the dead code and rebased this commit.

[sshaulnv]

Merged, thanks for your contribution!