From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Mintz, Yuval" Subject: Re: [RFC 02/11] Add RoCE driver framework Date: Wed, 14 Sep 2016 08:15:23 +0000 Message-ID: References: <1473696465-27986-1-git-send-email-Ram.Amrani@qlogic.com> <1473696465-27986-3-git-send-email-Ram.Amrani@qlogic.com> <516b98c7-477a-4890-0d92-529dc32f2c4e@mellanox.com> <20160913063806.GP8812@leon.nu> ,<20160913101616.GT8812@leon.nu> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20160913101616.GT8812-2ukJVAZIZ/Y@public.gmane.org> Content-Language: en-US Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Leon Romanovsky Cc: Yuval Mintz , Mark Bloch , Ram Amrani , "dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , David Miller , Ariel Elior , Michal Kalderon , Rajesh Borundia , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , netdev List-Id: linux-rdma@vger.kernel.org > > >> >> +uint debug; > > >> >> +module_param(debug, uint, 0); > > > >>> +MODULE_PARM_DESC(debug, "Default debug msglevel"); > > >> > > >> >Why are you adding this as a module parameter? > > >> > > >>=A0 I believe this is mostly to follow same line as qede which also d= efines > > > > 'debug' module parameter for allowing easy user control of debug > > > > prints [& specifically for probe prints, which can't be controlled > > > > otherwise]. > > > > > Can you give us an example where dynamic debug and tracing infrastruc= tures > > > are not enough? > > > > > AFAIK, most of these debug module parameters are legacy copy/paste > > > code which is useless in real life scenarios. > > > > Define 'enough'; Using dynamic debug you can provide all the necessary > > information and at an even better granularity that's achieved by sugges= ted > > infrastructure,=A0 but is harder for an end-user to use. Same goes for = tracing. > > > > The 'debug' option provides an easy grouping for prints related to a sp= ecific > > area in the driver. >=20 > It is hard to agree with you that user which knows how-to load modules > with parameters won't success to enable debug prints. I think you're giving too much credit to the end-user. :-D > In addition, global increase in debug level for whole driver will create > printk storm in dmesg and give nothing to debuggability. So basically, what you're claiming is that ethtool 'msglvl' setting for dev= ices is completely obselete. While this *might* be true, we use it extensively in our qede and qed drivers; The debug module parameter merely provides a manner of setting the debug value prior to initial probe for all interfac= es. qedr follows the same practice. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html