DragonFly bugs List (threaded) for 2008-07
Re: hammer_alloc_data panic
:> *some* of the space in each of those 16 blocks while filling up a new
:> block, but the new block may become completely full before any one of those
:> 16 blocks becomes completely empty. So another new block needs
:> to be allocated.
:Oh I see, that's in clear contrast to LFS. Is it possible to find all
:b-tree elements (or rather, their parents) when looking at one block?
... by scanning the B-Tree yes. With some sort of direct lookup? No.
This is the trade-off I made using a coarse-grained storage layer verses
the A-list based fine-grained one I originally envisioned. Though
nothing prevents HAMMER from being able to use a fine-grained storage
layer, if we can swing using the coarse-grained layer we reap some
phenominal advantages, not the least of which being that the management
overhead of the storage layer outside the reblocking function is about
as close to 0 as it is possible to get.