[PATCH 0/2] split index extra bits

This patch series contains 2 patches that have already been sent to the list but have felt through the cracks. It would be nice if they could be considered for v2.13.0.

Patch 1/2 (split-index: add and use unshare_split_index()) by Duy fixes a memory leak when a new shared index file is created and memory used by the old one should be freed.

Patch 2/2 (p3400: add perf tests for rebasing many changes) adds a test in t/perf that can help see what performance improvements can be gained by using the split index feature. For example using this patch at one point I got the following results on a Linux machine on the Git repository:

Test v2.10.0 v2.11.0 v2.12.0 origin/master ------------------------------------------------------------------------------------------------------------------------------------------------------------ 3400.2: rebase on top of a lot of unrelated changes 2.62(2.19+0.55) 2.54(2.15+0.49) -3.1% 2.59(2.19+0.49) -1.1% 2.66(2.27+0.52) +1.5% 3400.4: rebase a lot of unrelated changes without split-index 14.08(10.12+3.92) 7.20(5.85+1.36) -48.9% 8.06(6.54+1.60) -42.8% 7.53(6.40+1.12) -46.5% 3400.6: rebase a lot of unrelated changes with split-index 14.10(10.11+3.94) 6.94(5.71+1.27) -50.8% 7.99(6.49+1.57) -43.3% 6.10(5.12+1.07) -56.7%

On bigger repositories results are likely to be better.

Christian Couder (1):
  p3400: add perf tests for rebasing many changes

Nguyễn Thái Ngọc Duy (1):
  split-index: add and use unshare_split_index()

 read-cache.c           | 10 ++-------
 split-index.c          | 57 ++++++++++++++++++++++++++++++++++++++------------
 split-index.h          |  1 +
 t/perf/p3400-rebase.sh | 22 ++++++++++++++++++-
 4 files changed, 68 insertions(+), 22 deletions(-)