Messages in this thread | | | Date | Tue, 15 Jan 2013 23:37:42 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] printk: Avoid softlockups in console_unlock() |
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On Tue, 15 Jan 2013 18:58:34 +0100 Jan Kara <jack@suse.cz> wrote:
> A CPU can be caught in console_unlock() for a long time (tens of seconds are > reported by our customers) when other CPUs are using printk heavily and serial > console makes printing slow. This triggers softlockup warnings because > interrupts are disabled for the whole time console_unlock() runs (e.g. > vprintk() calls console_unlock() with interrupts disabled).
It should trigger the NMI watchdog in that case?
> We fix the issue by printing at most 1 KB of messages (unless we are in an > early boot stage or oops is happening) in one console_unlock() call. The rest > of the buffer will be printed either by further callers to printk() or by a > queued work.
Complex. Did you try just putting a touch_nmi_watchdog() in the loop?
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