Re: Using qsort(3) in the kernel

[Anders Magnusson <ragge%ludd.ltu.se@localhost>]

Martin S. Weber wrote:
> On Sun, Nov 16, 2008 at 01:41:34PM -0500, Steven M. Bellovin wrote:
>> (...)
>> The kernel stack is limited in size; if the recursion is too deep, it
>> can exceed that limit.  It's only safe to do recursion if you can (a)
>> guarantee the maximum depth; and (b) show that for all uses of this
>> routine, the total stack consumption will be low enough.
> 
> Doesn't gcc 4 in the meantime finally support that 70s technique of
> tail call optimization? Thought I had read about that somewhen.. could
> be mistaken tho.
> 
Yes, gcc does, but that doesn't mean that it can use it for the qsort 
recursions.
Not all recursive calls can be optimized away.

-- Ragge