git: hammer2 - freemap part 2 - cleanup & performance pass

[Matthew Dillon]

commit 512beabd66d77a7cca8f73bf69030ffa90f0b9e3
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date:   Fri May 17 18:17:47 2013 -0700

    hammer2 - freemap part 2 - cleanup & performance pass
    
    * Increase minimum I/O from 1K to 16K (HAMMER2_LBUFSIZE).
    
    * Adjust some use cases, increasing the smallest indirect block to the
      minimum IO size 4K->16K.
    
    * The BREF_TYPE_FREEMAP_LEAF bitmap is now embedded in the chain, allowing
      us to use the 256 byte bitmaps more safely.  As with inodes, a read-in
      involves using a larger buffer-cache buffer and then copying the data
      into the chain.
    
    * Avoid unnecessary reads from disk when allocating blocks that are less
      than the minimum IO size.  If it is determined that the bitmap bits
      covering the minimum IO size are 0 (unallocated), we pre-validate the
      larger buffer cache buffer so the later bread() does not have to issue
      any actual reads.
    
      Pre-validation for allocations larger than or equal to the minimum IO
      size is already handled in the chain locking code.
    
      With this change, a cpdup into H2 will issue mostly writes and is able
      to avoid nearly all reads.
    
    * Make some progress formalizing chain-embedded data.

Summary of changes:
 sys/vfs/hammer2/hammer2.h         |  2 +-
 sys/vfs/hammer2/hammer2_chain.c   | 62 +++++++++++++++++++++-------
 sys/vfs/hammer2/hammer2_disk.h    | 20 +++++----
 sys/vfs/hammer2/hammer2_flush.c   | 87 ++++++++++++++++++++++-----------------
 sys/vfs/hammer2/hammer2_freemap.c | 67 ++++++++++++++++++++++++------
 sys/vfs/hammer2/hammer2_inode.c   | 17 --------
 sys/vfs/hammer2/hammer2_subr.c    |  4 +-
 sys/vfs/hammer2/hammer2_vfsops.c  |  4 ++
 sys/vfs/hammer2/hammer2_vnops.c   |  4 +-
 9 files changed, 173 insertions(+), 94 deletions(-)

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/512beabd66d77a7cca8f73bf69030ffa90f0b9e3


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