From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergey Senozhatsky Subject: Re: [PATCH 4/4] printk: Add a device attribute for the per-console loglevel Date: Fri, 8 Mar 2019 12:11:21 +0900 Message-ID: <20190308031121.GA2480@jagdpanzerIV> References: <4f71564063a07837e3c4df41326bad25e7dc4db4.1551486733.git.calvinowens@fb.com> <20190304080630.GA4495@jagdpanzerIV> <20190304191006.GA51516@calvinowens-mba.dhcp.thefacebook.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190304191006.GA51516@calvinowens-mba.dhcp.thefacebook.com> Sender: linux-kernel-owner@vger.kernel.org To: Calvin Owens Cc: Sergey Senozhatsky , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Greg Kroah-Hartman , Jonathan Corbet , "linux-kernel@vger.kernel.org" , "linux-serial@vger.kernel.org" List-Id: linux-serial@vger.kernel.org On (03/04/19 19:10), Calvin Owens wrote: > On Monday 03/04 at 17:06 +0900, Sergey Senozhatsky wrote: > > On (03/01/19 16:48), Calvin Owens wrote: > > > +static struct attribute *console_sysfs_attrs[] = { > > > + &dev_attr_loglevel.attr, > > > + NULL, > > > +}; > > > +ATTRIBUTE_GROUPS(console_sysfs); > > > + > > > static struct bus_type console_subsys = { > > > .name = "console", > > > + .dev_groups = console_sysfs_groups, > > > }; > > > > Do we really need to change this dynamically? Console options are > > traditionally static (boot param or DT). Can we also be happy with > > the static per-console loglevel? > > It really does need to be runtime configurable: there are a lot of usecases > that enables, like turning the fast console up to KERN_DEBUG on a pile of > machines you want to take a closer look at. The 'kernel.printk' global > loglevel is also already changable at runtime, and since that setting > interacts with this one it would be strange if only the former were able > to be changed. Fair enough. -ss