Re: [PATCH] Increase maximum size of dmesg buffer to 16MB.

[Luis R. Rodriguez]

On Fri, Dec 12, 2014 at 02:38:26PM -0800, Vinson Lee wrote:
> From: Nate Stahl <stahl@xxxxxxxxxxx>
> 
> A full task stack dump of all tasks on a machine can generate more than
> 4MB of output to dmesg. Dumping this data to the serial console causes
> the machine to hang for a number of minutes (an unacceptable impact),
> but dumping the same data to memory is feasible if the dmesg buffer is
> sized large enough to hold the output. Set to 16MB which will hopefully
> be large enough to handle a dump from any of our servers at this time.
> 
> Signed-off-by: Nate Stahl <stahl@xxxxxxxxxxx>
> Signed-off-by: Vinson Lee <vlee@xxxxxxxxxxx>

Isn't this the perpetual issue of having large number of CPUs? If so
consider use of LOG_CPU_MAX_BUF_SHIFT instead, otherwise clarifying how
this would be a different issue would be good. LOG_CPU_MAX_BUF_SHIFT
should scale nicely but you can increase it as well, is it being used?

 Luis
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