pack, ... [but it is] the thing that gives packs good locality. It keeps the objects close to the head (whether they are old or new, but they are _reachable_ from the head) at the head of the pack. So packs actually have absolutely _wonderful_ IO patterns.”
pack, the objects we are _not_ going to pack but we know about are sorted earlier than other objects. • we always prefer to delta against objects we are not going to send, if there are some. • for "thin" packs only. used when the other side is known to have such objects.
spawn when searching for best delta matches. This requires that pack-objects be compiled with pthreads otherwise this option is ignored with a warning. This is meant to reduce packing time on multiprocessor machines. The required amount of memory for the delta search window is however multiplied by the number of threads. Specifying 0 will cause Git to auto-detect the number of CPU's and set the number of threads accordingly.