Messages in this thread | | | Date | Tue, 21 Feb 2006 04:09:58 -0500 (EST) | From | Ingo Molnar <> | Subject | Re: softlockup interaction with slow consoles |
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On Mon, 20 Feb 2006, David S. Miller wrote:
> When register_console() runs, it dumps the entire log buffer to the > console device with interrupts off. > > If you're going over a slow console, this can easily take more than 10 > seconds especially on SMP with many cpus brought up. > > This makes the softlock fire, which is terribly annoying :-) > > I think the bug is in the console registry code, I think it should > capture chunks of the existing console buffer into some local memory and > push things piece by piece with interrupts enabled to the console > driver(s). > > Any better ideas?
is this a boot-time-only problem? In recent updates to the softlockup code in -mm:
timer-irq-driven-soft-watchdog-cleanups.patch timer-irq-driven-soft-watchdog-percpu-race-fix.patch timer-irq-driven-soft-watchdog-percpu-fix.patch timer-irq-driven-soft-watchdog-boot-fix.patch
i changed soft lockup detection to be turned off during bootup. That should work around any boot-time warnings.
(if this can happen on a booted up system then the real fix would indeed be to split up register_console()'s workload - that would also make it more preemption-friendly. But at first sight it looks quite complex to do.)
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