Messages in this thread | | | Subject | Re: [debug patch] printk: Add a printk killswitch to robustify NMI watchdog messages | From | Peter Zijlstra <> | Date | Mon, 06 Jun 2011 18:12:51 +0200 |
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On Mon, 2011-06-06 at 18:08 +0200, Ingo Molnar wrote: > * Peter Zijlstra <peterz@infradead.org> wrote: > > > On Mon, 2011-06-06 at 17:52 +0200, Ingo Molnar wrote: > > > * Peter Zijlstra <peterz@infradead.org> 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? > > Yes, and we already do it in some other circumstances.
We do?
> Can you see > any problem with that? klogd is an utter slowpath anyway.
but console_sem isn't klogd. We delay klogd and that's perfectly fine, but afaict we don't delay console_sem.
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