[Celinux-dev] support for printk times control at runtime

[Tim Bird]

Hey all,

I just noticed a feature that was added by Jan Engelhardt some time ago,
which allows for runtime control of the printk times feature.

Here is what Jan wrote, in early June:
> Currently, enabling/disabling printk timestamps is only possible through 
> reboot (bootparam) or recompile. I normally do not run with timestamps 
> (since syslog handles that in a good manner), but for measuring small 
> kernel delays (e.g. irq probing - see parport thread) I needed subsecond 
> precision, but then again, just for some minutes rather than all kernel 
> messages to come.
> The following patch adds a module_param() with which the timestamps can be 
> en-/disabled in a live system through 
> /sys/modules/printk/parameters/printk_time.

This patch is now in mainline (2.6.18-rc3), so it should appear in the 2.6.18
kernel.

I put some information about this on the PrintkTimes page on the wiki:
http://tree.celinuxforum.org/CelfPubWiki/PrintkTimes

 -- Tim


=============================
Tim Bird
Architecture Group Chair, CE Linux Forum
Senior Staff Engineer, Sony Electronics
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