Messages in this thread | | | Date | Thu, 15 Dec 2016 18:23:36 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] MAINTAINERS: Add printk maintainers |
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On Thu, Dec 15, 2016 at 12:20:27PM -0500, Steven Rostedt wrote: > On Thu, 15 Dec 2016 18:12:00 +0100 > Peter Zijlstra <peterz@infradead.org> wrote: > > > On Thu, Dec 15, 2016 at 03:34:43PM +0100, Petr Mladek wrote: > > > We have to find the right balance. For example, we do not show > > > messages immediately in NMI context because there is a risk > > > of a deadlock. > > > > I find the occasional deadlock much preferable to guaranteed no output. > > Right, we can't stress the importance of getting output out when it > happens. A printk dump is the first course of action when debugging a > crash. And the printk output shows how much progress the computer made. > > If all printks are asynchronous, that will be unreliable information.
No, that will be _no_ information, since the 'later' part that does the flush will never happen.
> And really, that information can be extremely useful, but only if it is > reliable, otherwise, it becomes useless.
Well, if you want reliable get a UART and those 3 patches I did to force early_printk :-)
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