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* [PATCH 0/4] index-pack improvements
@ 2012-02-25 10:56 Nguyễn Thái Ngọc Duy
  2012-02-25 10:56 ` [PATCH 1/4] index-pack --verify: skip sha-1 collision test Nguyễn Thái Ngọc Duy
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Nguyễn Thái Ngọc Duy @ 2012-02-25 10:56 UTC (permalink / raw)
  To: git; +Cc: Nguyễn Thái Ngọc Duy

The first two patches are posted already, which help keep memory usage
down in the present of large blobs. The forth patch attempts to
resolve deltas in parallel.

$ time ./git index-pack --threads=1 --verify -v XXXX
Indexing objects: 100% (165375/165375), done.
Resolving deltas: 100% (124749/124749), done.

real    1m15.470s
user    1m14.899s
sys     0m0.552s

$ time ./git index-pack --threads=2 --verify -v XXXX
Indexing objects: 100% (165375/165375), done.
Resolving deltas: 100% (124749/124749), done.

real    0m41.339s
user    1m15.116s
sys     0m0.680s

$ time ./git index-pack --threads=3 --verify -v XXXX
Indexing objects: 100% (165375/165375), done.
Resolving deltas: 100% (124749/124749), done.

real    0m37.008s
user    1m35.742s
sys     0m0.803s

$ time ./git index-pack --verify -v XXXX   # four core machine
Indexing objects: 100% (165375/165375), done.
Resolving deltas: 100% (124749/124749), done.

real    0m33.701s
user    1m51.316s
sys     0m0.768s

$ time ./git index-pack --threads=8 --verify -v XXXX
Indexing objects: 100% (165375/165375), done.
Resolving deltas: 100% (124749/124749), done.

real    0m33.638s
user    1m51.783s
sys     0m0.773s

So there's improvement from user persepective, but overhead is too
high (user time from 1m14 to 1m51). Making threaded_second_pass to
process 512 consecutive objects each iteration to reduce contention on
work_mutex does not help. Any ideas?

Nguyễn Thái Ngọc Duy (4):
  index-pack --verify: skip sha-1 collision test
  index-pack: reduce memory usage when the pack has large blobs
  index-pack: move second pass code into separate function
  index-pack: support multithreaded delta resolving

 Documentation/config.txt         |    4 +
 Documentation/git-index-pack.txt |   10 ++
 Makefile                         |    2 +-
 builtin/index-pack.c             |  298 +++++++++++++++++++++++++++++++-------
 4 files changed, 260 insertions(+), 54 deletions(-)

-- 
1.7.8.36.g69ee2

^ permalink raw reply	[flat|nested] 5+ messages in thread

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2012-02-25 10:56 [PATCH 0/4] index-pack improvements Nguyễn Thái Ngọc Duy
2012-02-25 10:56 ` [PATCH 1/4] index-pack --verify: skip sha-1 collision test Nguyễn Thái Ngọc Duy
2012-02-25 10:56 ` [PATCH 2/4] index-pack: reduce memory usage when the pack has large blobs Nguyễn Thái Ngọc Duy
2012-02-25 10:56 ` [PATCH 3/4] index-pack: move second pass code into separate function Nguyễn Thái Ngọc Duy
2012-02-25 10:56 ` [PATCH 4/4] index-pack: support multithreaded delta resolving Nguyễn Thái Ngọc Duy

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