On Fri, 18 Apr 2014 11:54:38 -0700 Andrew Morton <a...@linux-foundation.org> wrote:
> On Wed, 26 Mar 2014 20:28:15 +0100 Jan Kara <j...@suse.cz> wrote: > > > > All the afflicted consoles are serial, all go via the uart layer as far > > > as I can see. > > > > > > The uart layer has a queue mechanism that could be used > > I'm sorry, I don't follow here - what can the uart queueing be used for? > > Alan, I'm desperate to avoid adding all this complexity to core printk > code to solve such a rare problem. It'd be great if you could flesh out > any alternative ideas please. It's not worth adding for upstream anyway - not in that form. If it just used schedule_work it would be way way cleaner anyway. For the general buffering case we already have tty_write_message(). It's only really intended for use by the old quota code so it's currently assuming nul terminated string but thats a trivial detail. For that matter I don't see why such systems can't implement a queuecon console which is a queue on the printk side and a fifo on the userspace side. The implementation then becomes trivial. If you want reliable crash logging then we need to be able to set a printk level mask per console and just set the serial console for "crit/err" and the queue console for the rest, with a 'cat >/dev/ttywhatever' running if this feature was in use ? Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
