daemon shutdown time with large zones (bind 9.2.4)

[Chris Timmons]

> - did you try that with or without ISC_MEM_USE_INTERNAL_MALLOC (or
>   both)?  After re-checking the patch, I noticed it was not effective
>   when ISC_MEM_USE_INTERNAL_MALLOC is enabled.  (sorry, this was my
>   bad again).

I tried it without ISC_MEM_USE_INTERNAL_MALLOC (since that was the
original worst-case), and the time stayed about the same as the
worst-case.

> - did you see the long period to shutdown the server even just after
>   starting it?  If the bottleneck is not really in the memory
>   management but in that code traversing the DB structure, the problem
>   should occur even if the server does no actual work (i.e., only just
>   loading and destroying the DB).

My testing scenario has been to run the daemon in the foreground with
"-g", and then shutdown via ^C as soon as the large zone has been loaded.
So we are just loading and destroying the DB.

-Chris