Hi All, We are running 3.8 kernel. I have a unique scenario, where we hit on several issues in do_coredump. We have a SMP system with thousands of cores, one pthread is tied to one core. The main process containing these pthreads runs in the first core. Here is the issue # 1 When one of threads core dump, we enter into do_coredump(), now one other thread in same process running in a different core can as well core dump(before SIGKILL was delivered to it as a consequence of first core dump) This gives way to entering into do_coredump more than once. Once we have two guys entering do_coredump() one can kill other with SIGKILL the result is completely unpredictable. No guarantee we will have two core files generated in the end Linux kernel does not seem to handle it at all. Adding a spin lock within do_coredump() will solve the case of multiple entries into do_coredump() I want to know whether Linux kernel really does not handle the above case or am I missing something? Please clarify Issue # 2: Within do_coredump() SIGKILL is sent to all threads in process other than the one running core dump. There is no guarantee that SIGKILL will be immediately received by all threads in the process, which means the state of threads (particularly backtrace per thread) can be lot of different now when compared to the time at which offending thread initiated a coredump. This is in turn means the core dump generated, will have a backtrace per thread, which is not accurate Please confirm my understanding, advice on how this problem can be solved Thanks, Sudharsan _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
