Mercurial > hg
view tests/test-issue672.t @ 44363:f7459da77f23
nodemap: introduce an option to use mmap to read the nodemap mapping
The performance and memory benefit is much greater if we don't have to copy all
the data in memory for each information. So we introduce an option (on by
default) to read the data using mmap.
This changeset is the last one definition the API for index support nodemap
data. (they have to be able to use the mmaping).
Below are some benchmark comparing the best we currently have in 5.3 with the
final step of this series (using the persistent nodemap implementation in
Rust). The benchmark run `hg perfindex` with various revset and the following
variants:
Before:
* do not use the persistent nodemap
* use the CPython implementation of the index for nodemap
* use mmapping of the changelog index
After:
* use the MixedIndex Rust code, with the NodeTree object for nodemap access
(still in review)
* use the persistent nodemap data from disk
* access the persistent nodemap data through mmap
* use mmapping of the changelog index
The persistent nodemap greatly speed up most operation on very large
repositories. Some of the previously very fast lookup end up a bit slower because
the persistent nodemap has to be setup. However the absolute slowdown is very
small and won't matters in the big picture.
Here are some numbers (in seconds) for the reference copy of mozilla-try:
Revset Before After abs-change speedup
-10000: 0.004622 0.005532 0.000910 × 0.83
-10: 0.000050 0.000132 0.000082 × 0.37
tip 0.000052 0.000085 0.000033 × 0.61
0 + (-10000:) 0.028222 0.005337 -0.022885 × 5.29
0 0.023521 0.000084 -0.023437 × 280.01
(-10000:) + 0 0.235539 0.005308 -0.230231 × 44.37
(-10:) + :9 0.232883 0.000180 -0.232703 ×1293.79
(-10000:) + (:99) 0.238735 0.005358 -0.233377 × 44.55
:99 + (-10000:) 0.317942 0.005593 -0.312349 × 56.84
:9 + (-10:) 0.313372 0.000179 -0.313193 ×1750.68
:9 0.316450 0.000143 -0.316307 ×2212.93
On smaller repositories, the cost of nodemap related operation is not as big, so
the win is much more modest. Yet it helps shaving a handful of millisecond here
and there.
Here are some numbers (in seconds) for the reference copy of mercurial:
Revset Before After abs-change speedup
-10: 0.000065 0.000097 0.000032 × 0.67
tip 0.000063 0.000078 0.000015 × 0.80
0 0.000561 0.000079 -0.000482 × 7.10
-10000: 0.004609 0.003648 -0.000961 × 1.26
0 + (-10000:) 0.005023 0.003715 -0.001307 × 1.35
(-10:) + :9 0.002187 0.000108 -0.002079 ×20.25
(-10000:) + 0 0.006252 0.003716 -0.002536 × 1.68
(-10000:) + (:99) 0.006367 0.003707 -0.002660 × 1.71
:9 + (-10:) 0.003846 0.000110 -0.003736 ×34.96
:9 0.003854 0.000099 -0.003755 ×38.92
:99 + (-10000:) 0.007644 0.003778 -0.003866 × 2.02
Differential Revision: https://phab.mercurial-scm.org/D7894
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Tue, 11 Feb 2020 11:18:52 +0100 |
parents | 17e12938f8e7 |
children | 69429972ff1f |
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https://bz.mercurial-scm.org/672 # 0-2-4 # \ \ \ # 1-3-5 # # rename in #1, content change in #4. $ hg init $ touch 1 $ touch 2 $ hg commit -Am init # 0 adding 1 adding 2 $ hg rename 1 1a $ hg commit -m rename # 1 $ hg co -C 0 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo unrelated >> 2 $ hg ci -m unrelated1 # 2 created new head $ hg merge --debug 1 unmatched files in other: 1a all copies found (* = to merge, ! = divergent, % = renamed and deleted): on remote side: src: '1' -> dst: '1a' checking for directory renames resolving manifests branchmerge: True, force: False, partial: False ancestor: 81f4b099af3d, local: c64f439569a9+, remote: c12dcd37c90a 1: other deleted -> r removing 1 1a: remote created -> g getting 1a 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m merge1 # 3 $ hg co -C 2 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo hello >> 1 $ hg ci -m unrelated2 # 4 created new head $ hg co -C 3 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg merge -y --debug 4 unmatched files in local: 1a all copies found (* = to merge, ! = divergent, % = renamed and deleted): on local side: src: '1' -> dst: '1a' * checking for directory renames resolving manifests branchmerge: True, force: False, partial: False ancestor: c64f439569a9, local: f4a9cff3cd0b+, remote: 746e9549ea96 preserving 1a for resolve of 1a starting 4 threads for background file closing (?) 1a: local copied/moved from 1 -> m (premerge) picked tool ':merge' for 1a (binary False symlink False changedelete False) merging 1a and 1 to 1a my 1a@f4a9cff3cd0b+ other 1@746e9549ea96 ancestor 1@c64f439569a9 premerge successful 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg co -C 4 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg merge -y --debug 3 unmatched files in other: 1a all copies found (* = to merge, ! = divergent, % = renamed and deleted): on remote side: src: '1' -> dst: '1a' * checking for directory renames resolving manifests branchmerge: True, force: False, partial: False ancestor: c64f439569a9, local: 746e9549ea96+, remote: f4a9cff3cd0b preserving 1 for resolve of 1a removing 1 starting 4 threads for background file closing (?) 1a: remote moved from 1 -> m (premerge) picked tool ':merge' for 1a (binary False symlink False changedelete False) merging 1 and 1a to 1a my 1a@746e9549ea96+ other 1a@f4a9cff3cd0b ancestor 1@c64f439569a9 premerge successful 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit)