[mpich-discuss] mpich2 hangs on Ubuntu beowulf cluster(with NFS)

[Nicolas Rosner]

Hi Kwstas,

> One question. If the code deadlocks
> when using the two machines
> shouldn it deadlock when running
> on each machine seperately

Nope. At least not in the general case. In fact, more often than not,
what you say will indeed prevent deadlock-prone code from showing any
symptoms.

Typically, deadlock arises with more than one participant and in some
situations only.

(This does not mean that a single process cannot deadlock with itself,
or that some code will deadlock every single time, e.g. Ssend()ing to
self should indeed fail every time and even if there is no-one else to
deadlock with. But those cases are not as common as the typical,
OS-textbook deadlock case where A waits until B does what B won't do
until A does something else.)