DragonFly kernel List (threaded) for 2008-02
DragonFly BSD
DragonFly kernel List (threaded) for 2008-02
[Date Prev][Date Next]  [Thread Prev][Thread Next]  [Date Index][Thread Index]

Re: HAMMER update 06-Feb-2008


From: Ivan Voras <ivoras@xxxxxxxxxxx>
Date: Thu, 07 Feb 2008 01:05:23 +0100

Matthew Dillon wrote:

    * Get rid of the A-list's (the recursive bitmap radix tree allocation
      model).  Poof, gone.  All of them, gone.  Have no random block
      allocation model at all.

    * Get rid of the per-cluster B-Tree's.  Instead have just one global
      B-Tree for the entire filesystem, able to access any record anywhere
      in the filesystem (currently a per-cluster B-Tree can only access
      information within that cluster).

    * Implement the filesystem as one big huge circular FIFO, pretty much
      laid down linearly on disk, with a B-Tree to locate and access data.

How will this affect parallel IO (reads, but especially writes)? Would having such a global structure serialize it? (I'm assuming, possibly wrongly, that having trees per-cluster allowed you to lock individual clusters).




Attachment: signature.asc
Description: OpenPGP digital signature



[Date Prev][Date Next]  [Thread Prev][Thread Next]  [Date Index][Thread Index]