Re: [dpdk-dev] [PATCH v5 0/3] EAL change for using a config file for DPDK

[Thomas Monjalon <thomas@monjalon.net>]

23/01/2019 20:31, Ferruh Yigit:
> On 7/13/2017 11:07 AM, kubax.kozak at intel.com (Kuba Kozak) wrote:
> > This patchset introduce a mechanism for running dpdk application with 
> > parameters provided by configuration file.
> > 
> > A new API for EAL takes a config file data type - either loaded from
> > file, or built up programmatically in the application - and extracts
> > DPDK parameters from it to be used when eal init is called. 
> > This allows apps to have an alternative method to configure EAL,
> > other than via command-line parameters.
> > 
> > Reworked applications are used to demonstrate the new eal API.
> > If a --cfgfile-path <path> option is passed into command line non
> > EAL section, then the file is loaded and used by app. If a file
> > called config.ini is present in current working directory, and
> > no --cfgfile-path option is passed in, config.ini file will be
> > loaded and used by app.
> > 
> > Patch "app/testpmd: add parse options from JSON cfg file" 
> > demonstrates the usage of JSON instead of INI file format. 
> > JSON file can be called the same way as above, 
> > through --cfgfile-path <path> argument.
> > ---
> > this patch depends on:
> > "Rework cfgfile API to enable apps config file support"
> > 
> > v5:
> >   changed define "RTE_DEVTYPE_VIRTUAL" to "RTE_DEVTYPE_UNDEFINED"
> >   due to compilation errors (changes on current master).
> > 
> > v4:
> >  Code optimalisation in parse_vdev_devices() function.
> >  Moved some functions from librte_eal/bsdapp and librte_eal/linuxapp
> >  to the librte_eal/common.
> >  Bug fixes.
> > 
> > v3: 
> >  split one patchset into two distinct patchsets:
> >  1. cfgfile library and TEST app changes
> >  2. EAL changes and examples (this patchset depends on cfgfile)
> > 
> > v2:
> >   lib eal:
> > 	Rework of rte_eal_configure(struct rte_cfgfile *cfg, char *prgname).
> > 	Now this function load data from cfg structure and did initial
> > 	initialization of EAL arguments. Vdev argument are stored in different
> > 	subsections eg. DPDK.vdev0, DPDK.vdev1 etc. After execution of this
> > 	function it is necessary to call rte_eal_init to complete EAL
> > 	initialization. There is no more merging arguments from different
> > 	sources (cfg file and command line).
> >   	Added non_eal_configure to testpmd application.
> > 	Function maintain the same functionality as rte_eal_configure but
> > 	for non-eal arguments. 
> >   	Added config JSON feature to testpmd last patch from patchset contain
> > 	example showing use of .json configuration files.
> > 
> >   lib cfgfile:
> >   	Rework of add_section(), add_entry() new implementation
> >   	New members allocated_entries/sections, free_entries/sections
> > 	in rte_cfgfile structure, change in array of pointers
> > 	**sections, **entries instead of *sections[], *entries[]
> >   	Add  set_entry() to update/overwrite already existing entry in cfgfile
> > 	struct
> >   	Add save() function to save on disc cfgfile structure in INI format
> >   	Rework of existing load() function  simplifying the code
> >   	Add unit test realloc_sections() in TEST app for testing realloc/malloc
> > 	of new API functions, add test for save() function
> > 
> > Kuba Kozak (3):
> >   eal: add functions parsing EAL arguments
> >   app/testpmd: add parse options from cfg file
> >   app/testpmd: add parse options from JSON cfg file
> 
> This patchset is idle more than a year now.
> It solves problem of eal parameters, it doesn't remove them but at least moves
> from command line to config file.
> 
> The patch seems mostly done, but what is the status of it, do we want to
> continue it?
> And if we want to continue it can this be a good candidate for GCOS?

I think we must focus on reorganization of EAL first.
When the options parsing will be better isolated,
and accessible from API independant of rte_eal_init,
then we could provide some helpers to use those APIs
for a config file, a custom command line or anything else.