* Tejun Heo (tj@kernel.org) wrote:

Hello,

On Mon, Oct 29, 2012 at 12:14:12PM -0400, Mathieu Desnoyers wrote:

quoted

Most of the calls to this initialization function apply it on zeroed
memory (static/kzalloc'd...), which makes it useless. I'd actually be in
favor of removing those redundant calls (as I pointed out in another
email), and document that zeroed memory don't need to be explicitly
initialized.

Those sites that need to really reinitialize memory, or initialize it
(if located on the stack or in non-zeroed dynamically allocated memory)
could use a memset to 0, which will likely be faster than setting to
NULL on many architectures.

I don't think it's a good idea to optimize out the basic encapsulation
there.  We're talking about re-zeroing some static memory areas which
are pretty small.  It's just not worth optimizing out at the cost of
proper initializtion.  e.g. We might add debug fields to list_head
later.

Future-proofness for debugging fields is indeed a very compelling
argument. Fair enough!

We might want to document this intent at the top of the initialization
function though, just in case anyone want to short-circuit it.

Thanks,

Mathieu

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>