From mboxrd@z Thu Jan 1 00:00:00 1970 From: Erich Focht Date: Tue, 02 Oct 2001 09:16:12 +0000 Subject: [Linux-ia64] Re: deadlock in crashed multithreaded job Message-Id: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Mon, 1 Oct 2001, Manfred Spraul wrote: > > The symptoms: running the tests (make check) sometimes ends up > > with hanging processes. > > Does it _only_ hang during coredumping, or also during normal usage? > > Could you remove > down_read(&mmap_sem); > binfmt->coredump(); > up_read(&mmap_sem); > from fs/exec.c and rerun your tests? Setting the coredumpsize limit to 0 already solves the problem. The question that remains is how to deal with nested locks on the same resource that can lead to deadlocks. Is there any (un)written rule that one should avoid them in the Linux Kernel? Or are there any approaches to deal with them (which are not yet included in the Kernel)? > The hang during coredumping is known, there are 2 fixes [I have one, not > yet released, Andrea wrote one, IIRC included in his -aa kernels]. Do these solutions deal only with the coredump problem or with nested critical sections? Thanks, Erich