On 7/29/2018 6:33 AM, Nguyễn Thái Ngọc Duy wrote:
This series speeds up unpack_trees() a bit by using cache-tree. unpack-trees could bit split in three big parts - the actual tree unpacking and running n-way merging - update worktree, which could be expensive depending on how much I/O is involved - repair cache-tree This series focuses on the first part alone and could give 700% speedup (best case possible scenario, real life ones probably not that impressive). It also shows that the reparing cache-tree is kinda expensive. I have an idea of reusing cache-tree from the original index, but I'll leave that to Ben or others to try out and see if it helps at all. v2 fixes the comments from Junio, adds more performance tracing and reduces the cost of adding index entries. Nguyễn Thái Ngọc Duy (4): unpack-trees.c: add performance tracing unpack-trees: optimize walking same trees with cache-tree unpack-trees: reduce malloc in cache-tree walk unpack-trees: cheaper index update when walking by cache-tree cache-tree.c | 2 + cache.h | 1 + read-cache.c | 3 +- unpack-trees.c | 161 ++++++++++++++++++++++++++++++++++++++++++++++++- unpack-trees.h | 1 + 5 files changed, 166 insertions(+), 2 deletions(-)
I have a limited understanding of this code path so I'm not the best person to review this but I didn't see any issues that concerned me. I also was able to run our internal functional and performance tests in addition to the git tests and the results were positive.
Ben
