On Fri, Apr 18, 2014 at 08:49:53PM +0800, Lai Jiangshan wrote:
> The ida callers always calls ida_pre_get() before ida_get_new*().
> ida_pre_get() will do layer allocation, and ida_get_new*() will do layer removal.
> 
> It causes an unneeded ping-pong. The speculative layer removal in
> ida_get_new*() can't result expected optimization.
> 
> So we remove the unneeded layer removal in ida_get_new*().

But the as comment says, ida doesn't want to keep extra layers around
as it wants to keep its memory footprint minimal.  I think the right
thing to do is implementing ida_preload() which is simliar to
idr_preload() and do away with per-ida layer cache.

Thanks.

-- 
tejun