[PATCH] speed up tdbbackup

[Jeremy Allison]

On Wed, Jul 22, 2015 at 12:07:55PM +0200, Volker Lendecke wrote:
> Hi!
> 
> Attached find patches that speed up tdb measurably. I don't
> get really reliable results with "time", but I've seen up to
> 25% improvement on a 10-million small record tdb file on
> /dev/shm/. If I run a 1-million record tdbbackup, callgrind
> goes down from 6,916,115,142 to 4,888,697,132 instructions
> run. This pretty repeatable.
> 
> Now guess what patch has the larger effect... It's the
> tdb_oob one. I can only guess why this is the case. Probably
> pointer chasing is really expensive and the CPU caches are
> better utilized if we can call a common function.
> 
> Review&push appreciated!

Just fyi - looks good to me but I got an autobuild
fail on push, so I'll take a closer look !

Cheers,

	Jeremy.