On Thu, Oct 12, 2017 at 01:52:29PM +0200, Greg Kroah-Hartman wrote: > On Thu, Oct 12, 2017 at 01:34:39PM +0200, Peter Zijlstra wrote: > > On Thu, Oct 12, 2017 at 12:03:04PM +0200, Petr Mladek wrote: > > > On Thu 2017-10-12 11:45:37, Petr Mladek wrote: > > > > Hi, > > > > > > > > I thought about this a lot from several angles. And I would prefer > > > > sligly different placement, see the patch below. > > > > > > > > On Thu 2017-09-28 14:18:24, Peter Zijlstra wrote: > > > > > Some people figured vprintk_emit() makes for a nice API and exported > > > > > it, bypassing the kdb trap. > > > > > > > > Sigh, printk() API is pretty complicated and this export > > > > made it much worse. Well, there are two things: > > > > > > > > First, kdb_trap_printk name is a bit misleading. It is not a > > > > generic trap of any printk message. Instead it seems to be > > > > used to redirect only particular messages from some existing > > > > functions, e.g. show_regs() called from kdb_dumpregs(). > > > > > > > > Second, it seems that the only user of the exported vprintk_emit() > > > > is dev_vprintk_emit(). I believe that code using this wrapper > > > > is not called in the sections where kdb_trap_printk is incremented. > > > > > > Well, I wonder if we should go even further and stop exporting > > > vprintk_emit(). IMHO, the only reason was dev_print_emit() and > > > the ability to pass the extra "dict" parameter. > > > > You have my blessing there, but the device folks might have an opinion > > on that; Cc'ed Gregkh. > > Hm, we "need" that dict option, otherwise the whole dev_printk() family > of messages will not work properly, right? > > Or am I missing something? If you can figure out a way to still support > the same thing (we need a prefix at the beginning of the message that > shows the device/driver/binding/etc that emitted the message), that's > fine with me, I'm not wed to vprintk_emit() :)
Nope, this doesn't seem to deal with the prefix, except in some odd way that is tied to the dynamic debugging logic. I really don't know what this does anymore. Joe wrote it in 2012 as part of the dynamic debug code. Joe, any thoughts? thanks, greg k-h
