Re: linux hangs with printk on schedule()

["Haoqiang Zheng" <hzheng@cs.columbia.edu>]

> oops_in_progress++;
> printk(...);
> oops_in_progress--;

Thanks Robert and Andi for your help.
But the trick (avoid waking up klog by setting oops_in_progress) doesn't
seem to work for me.

I did notice the code:
*********************************************
 if (must_wake_klogd && !oops_in_progress)
  wake_up_interruptible(&log_wait);
*****************************************
But it simply still doesn't work. :-(

I am working on implementing a new SMP scheduler. It's an OS research
project. Without "printk" in the scheduler, it's really very hard to do the
debugging. I don't know how other guys do in this case. Are you guys better
equipped than me? I mean is debugging with gdb running on another machine
(connected via serial port) a common technique? I am not sure whether it's
necessary to set up an environment like that.

Haoqiang