Re: [PATCH] fs/devfs/base.c

[Bill Pringlemeir <bpringle@sympatico.ca>]

>>>>> "Richard" == Richard Gooch <rgooch@ras.ucalgary.ca> writes:
[snip]
 > I guess we should ask the question as to what's an
 > acceptable usage.  Theoretically, any amount could pose a
 > problem, but that's hardly a useful position to work

There was a discussion on comp.arch.embedded about bounded stack use.
It is fairly easy to calculate the stack usage for call trees, but
much more difficult for `DAGs'.  Ie, a recursive functions etc.  I
don't know about the policy on recursion in the kernel, but I think it
would be bad.

Perhaps the checker could be modified to keep track of the call tree
and find the largest value used in the tree.  Each function will have
a maximum, to which you should add the interrupt handling overhead,
which would be calculated in a similar way.  This will work if you do
not allow re-entrant interrupts and you do not have any `cycles' in the
function call hierarchies.

hth,
Bill Pringlemeir.