printks in the scheduler freeze during scripts

I'm running linux 2.4.17 and Redhat 7.2 with the preemptive and low latency patches, and whenever I stick printks in the scheduler(void) my system freezes somewhere after it tries to load the system font. Where it stops seems to be random. I can only run under single user mode without my system freezing. Does anyone have any clues why? Or any better ways to go about tracking the scheduling of processes in the scheduler?

Anton

Camotion
Software Development
678-471-0895

printk() calls wake_up(), to give klogd a kick. So a printk from the scheduler tends to deadlock. Just delete the last two lines of kernel/printk.c:release_console_sem() and it should work OK.

Something I have used in my testing:

Add, in the task structure:

task_t *sched_from;

In schedule, prior to context_switch:

next->sched_from = prior; /* at this point still == get_current ()*/

Somewhere else (so you don't inadvertantly side-effect to death schedule()):

Follow the back-link and printk whatever for the task that you are interested in, being careful not to reference task structures that no longer exist.

Mike