Messages in this thread | | | Date | Fri, 30 Nov 2012 15:21:49 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] Avoid dead lock of console related locks in panic case |
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On Fri, 30 Nov 2012 22:59:13 +0000 Seiji Aguchi <seiji.aguchi@hds.com> wrote:
> > > > Let's step back a bit. Please identify with great specificity the code sites which are stopping other CPUs before taking locks which > > those other CPUs might have been holding. > > > > Then let's see what we can do to fix up the callers, instead of trying to tidy up after they have made this mess. > > OK. > I will update my patch without adding complexity. > The logic will be as follows, if I understand your comment correctly. > > - take console related locks (logbuf_lock, console_sem) > - stop other cpus > - release those locks
That would be one way around the problem. It's still a bit messy, because we'll have to take more and more locks in the future, as we identify them.
What I actually meant was: can "this" CPU avoid stopping other CPUs so early? If we stop the other CPUs when this CPU is ready to stop itself then there will never be such deadlocks.
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