Hello, thanks for Cc-ing.
On (10/27/16 11:19), Petr Mladek wrote: [..] > Yeah, logbuf_lock is taken on many locations but logbuf_cpu is set > only in vprintk_emit(). It means that the other locations, including > console_unlock() are not protected against this type of recursion. > > There is actually a whole bunch of possible printk-related deadlocks. > There are several approaches how to handle some of them, for example: > > + printk_save(), see > > https://lkml.kernel.org/r/20161018154045.7364-1-sergey.senozhat...@gmail.com > > + async printk, see > > https://lkml.kernel.org/r/1459789048-1337-1-git-send-email-sergey.senozhat...@gmail.com > > + early console, see > https://lkml.kernel.org/r/20161018170830.405990...@infradead.org > > > The more we try to fix them, the more problems we see. Sergey probably > has the best overview about it at the moment. yep. I think I'll re-fresh my printk_safe patch set tonight. it will conflict with Linus' pr_cont() rework, so I'll keep my patch set as a RFC. > We are going to discuss a possible progress on Plumbers next week. yep. I'll prepare some PDF slides :) I'm afraid due to the lack of experience/time/"anything else that is crucially important" I have no idea at the moment if my KS tech-topic proposal [1][2] has been approved or rejected (is KS schedule available somewhere online already? I can't find it) and I absolutely forgot to submit it as a LPC micro-conference as a back-up plan (hm, can people actually do this?). so in the worst case (printk tech-topic is out of KS schedule) we will have to find an empty room on our own (I'm available *any* time). my apologies for any incontinence in advance. [1] https://lists.linuxfoundation.org/pipermail/ksummit-discuss/2016-July/002740.html [2] https://lists.linuxfoundation.org/pipermail/ksummit-discuss/2016-September/004006.html -ss
