On Tue, 2005-06-28 at 09:42 -0400, Guillaume Autran wrote: > Hi, > > I happen to notice a race condition in the mmu_context code for the 8xx > with very few context (16 MMU contexts) and kernel preemption enable. It > is hard to reproduce has it shows only when many processes are > created/destroy and the system is doing a lot of IRQ processing. > > In short, one process is trying to steal a context that is in the > process of being freed (mm->context == NO_CONTEXT) but not completely > freed (nr_free_contexts == 0). > The steal_context() function does not do anything and the process stays > in the loop forever. > > Anyway, I got a patch that fixes this part. Does not seem to affect > scheduling latency at all. > > Comments are appreciated.
Your patch seems to do a hell lot more than fixing this race ... What about just calling preempt_disable() in destroy_context() instead ? Ben.
