On 08/23, Oleg Nesterov wrote: > > However. I spent all Monday trying to resolve the new bug, and > so far I do not understand what happens. Extremely hard to reproduce, > and the kernel just hangs silently, without any message. > So far I suspect the proble in utrace.c, but this time I am not sure.
Solved. This was scheduler bug fixed in 2.6.35, but I used 2.6.34. This is really funny. This bug (PF_STARTING lockup) was found and fixed by me & Peter. Oh. But I hit yet another problem, BUG_ON() in __utrace_engine_release(). Again, it is not reproducible, I saw it only once in dmesg and I do not even know for sure what I was doing. I'll contiue tomorrow, but if I won't be able to quickly resolve this problem I am going to ignore it for now. This time I think ugdb is wrong. Oleg.