[PATCH/RFC v1 0/2] The ext4 filesystem and racy git

[Kjetil Barvik <barvik@broadpark.no>]

Ext4 is marked stable in Linux v2.6.28, and I have done a very simple
test on one disk-partition of my slow laptop, and the numbers look
very promising.

With default created ext3 disk-partition on my harddisk the 'git
checkout -q my-v2.6.25/27' test takes around 20 seconds real time for
the best cases.  The same test run on a ext4 partition takes around 14
seconds for the best cases.

And, since ext4 supports nanosecond timestamps, when I added patch
2/2, the checkout time is much more stable and more close to 14-15
seconds most of the time.

Conclusion: for GIT on my laptop the ext4 filesystem is a speedup!

>From '/proc/mounts' here is the mount options:

  /dev/hda10 /home ext3 rw,noatime,errors=continue,data=ordered 0 0
  /dev/hda12 /opt2 ext4 rw,noatime,barrier=1,journal_async_commit,data=ordered 0 0

/dev/hda10 is formatted with default (gentoo) ext3 parameters, and the
/dev/hda12 is formatted with:

  /sbin/mkfs -t ext4 -I 256 -G 64 -Oflex_bg,uninit_bg /dev/hda12


Kjetil Barvik (2):
  fix compile error when USE_NSEC is defined
  make USE_NSEC work as expected

 builtin-fetch-pack.c |    4 +-
 cache.h              |    6 ++--
 read-cache.c         |   70 ++++++++++++++++++++++++++++++++++++++++----------
 3 files changed, 61 insertions(+), 19 deletions(-)