On Mon, 2011-06-06 at 17:52 +0200, Ingo Molnar wrote: > * Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > > Needs more staring at, preferably by someone who actually > > understands that horrid mess :/ Also, this all still doesn't make > > printk() work reliably while holding rq->lock. > > So, what about my suggestion to just *remove* the wakeup from there > and use the deferred wakeup mechanism that klogd uses. > > That would make printk() *visibly* more robust in practice. That's currently done from the jiffy tick, do you want to effectively delay releasing the console_sem for the better part of a jiffy? > [ It would also open up the way to possibly make printk() NMI entry > safe - currently we lock up if we printk in an NMI or #MC context > that happens to nest inside a printk(). ] Well, for that to happen you also need to deal with logbuf_lock nesting. Personally I think using printk() from NMI context is quite beyond sane. -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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