Re: [dpdk-dev] [PATCH] app/testpmd: fix testpmd exit using ctrl+d

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Dumitrescu, Cristian
> Sent: Tuesday, July 24, 2018 5:59 PM
> To: Mordechay Haimovsky <motih@mellanox.com>; Thomas Monjalon <thomas@monjalon.net>; Singh, Jasvinder
> <jasvinder.singh@intel.com>
> Cc: dev@dpdk.org; Iremonger, Bernard <bernard.iremonger@intel.com>; Pattan, Reshma <reshma.pattan@intel.com>;
> olivier.matz@6wind.com
> Subject: Re: [dpdk-dev] [PATCH] app/testpmd: fix testpmd exit using ctrl+d
> 
> 
> 
> > -----Original Message-----
> > From: Mordechay Haimovsky [mailto:motih@mellanox.com]
> > Sent: Tuesday, July 24, 2018 3:37 PM
> > To: Thomas Monjalon <thomas@monjalon.net>; Singh, Jasvinder
> > <jasvinder.singh@intel.com>
> > Cc: dev@dpdk.org; Iremonger, Bernard <bernard.iremonger@intel.com>;
> > Pattan, Reshma <reshma.pattan@intel.com>; olivier.matz@6wind.com;
> > Dumitrescu, Cristian <cristian.dumitrescu@intel.com>
> > Subject: RE: [dpdk-dev] [PATCH] app/testpmd: fix testpmd exit using ctrl+d
> >
> > Even after this fix we still have setups that use netvsc  for example,  on
> > which testpmd exits with rte_panic right after loading it even without
> > touching the KBD.
> >
> > I recommend returning the previous prompt routine in test-pmd/cmdline.c
> > and rework the SOFTNIC section there, preferably moving its poll section to
> > use rte_service in a separate file cleaning the CLI files from PMD-specific
> > implementation.
> >
> > > -----Original Message-----
> > > From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > > Sent: Tuesday, July 24, 2018 3:34 PM
> > > To: Jasvinder Singh <jasvinder.singh@intel.com>
> > > Cc: dev@dpdk.org; bernard.iremonger@intel.com;
> > > reshma.pattan@intel.com; Mordechay Haimovsky
> > <motih@mellanox.com>;
> > > olivier.matz@6wind.com; cristian.dumitrescu@intel.com
> > > Subject: Re: [dpdk-dev] [PATCH] app/testpmd: fix testpmd exit using ctrl+d
> > >
> > > Important note:
> > > 	testpmd is currently really broken.
> > > 	We cannot have a RC2 until it is fixed.
> > >
> > >
> > > 24/07/2018 13:25, Thomas Monjalon:
> > > > 23/07/2018 12:44, Jasvinder Singh:
> > > > > Fix testpmd app exit by pressing ctrl+d, End-of-Transmission
> > > > > character (EOT) on the empty command line.
> > > >
> > > > Please describe what is the issue and what is the cause.
> > > >
> > > > > Fixes: 0ad778b398c6 ("app/testpmd: rework softnic forward mode")
> > > > >
> > > > > Reported-by: Mordechay Haimovsky <motih@mellanox.com>
> > > > > Signed-off-by: Jasvinder Singh <jasvinder.singh@intel.com>
> > > > > ---
> > > > >  app/test-pmd/cmdline.c       | 10 ++++++----
> > > > >  lib/librte_cmdline/cmdline.c |  2 +-
> > > >
> > > > It is very suspicious to change the cmdline library.
> > > > If there is a bug in this library, it deserves a separate fix.
> > >
> > >
> 
> 
> First, testpmd is not really broken, as only thing that changed is the Ctrl + D behavior. I agree this is an issue that we need to fix, as
> it looks that it is breaking some automation scripts for some people.
> 
> The change in behavior for Ctrl + D exit is caused by replacing the call to cmdline_interact() with calling cmdline_poll() in a loop.
> These two approaches should be identical in behavior, but it looks like they are not due to some issue in the cmdline library.
> Jasvinder proposed a quick patch, but it looks like something else needs to be fixed in cmdline library in order to bring
> cmdline_poll() on parity with cmdline_interact(). Any advice from Olivier would be very much appreciated!
> 
> It is really a bad practice to use cmdline_interact() in testpmd, as it is a blocking call that prohibits doing other things on the same
> thread that runs the CLI. Sometimes we need to run other things on the same core, e.g. the slow softnic_manage() function.

Curious why not use a service core for softnic background stuff, and leave CLI one for CLI? 
Konstantin

> 
> Worst case scenario: We can revert the cmdline_poll() back to cmdline_interact(), this is a small change, but not the proper way of
> doing things, as this is simply hiding the issue in cmdline library. It would also prevent us from testing some Soft NIC functionality.