Mercurial > hg
view tests/test-propertycache.py.out @ 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 | 9789670992d6 |
children |
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=== property cache === calllog: [] cached value (unfiltered): NOCACHE = first access on unfiltered, should do a call access: 0 calllog: [0] cached value (unfiltered): 0 = second access on unfiltered, should not do call access 0 calllog: [0] cached value (unfiltered): 0 = first access on "visible" view, should do a call cached value ("visible" view): NOCACHE access: 7 calllog: [0, 7] cached value (unfiltered): 0 cached value ("visible" view): 7 = second access on "visible view", should not do call access: 7 calllog: [0, 7] cached value (unfiltered): 0 cached value ("visible" view): 7 = no effect on other view cached value ("immutable" view): NOCACHE access: 9 calllog: [0, 7, 9] cached value (unfiltered): 0 cached value ("visible" view): 7 cached value ("immutable" view): 9 === unfiltered property cache === unficalllog: [] cached value (unfiltered): NOCACHE cached value ("visible" view): NOCACHE cached value ("immutable" view): NOCACHE = first access on unfiltered, should do a call access (unfiltered): 100 unficalllog: [100] cached value (unfiltered): 100 = second access on unfiltered, should not do call access (unfiltered): 100 unficalllog: [100] cached value (unfiltered): 100 = access on view should use the unfiltered cache access (unfiltered): 100 access ("visible" view): 100 access ("immutable" view): 100 unficalllog: [100] cached value (unfiltered): 100 cached value ("visible" view): NOCACHE cached value ("immutable" view): NOCACHE = even if we clear the unfiltered cache cached value (unfiltered): NOCACHE cached value ("visible" view): NOCACHE cached value ("immutable" view): NOCACHE unficalllog: [100] access ("visible" view): 100 unficalllog: [100, 100] cached value (unfiltered): 100 cached value ("visible" view): NOCACHE cached value ("immutable" view): NOCACHE access ("immutable" view): 100 unficalllog: [100, 100] cached value (unfiltered): 100 cached value ("visible" view): NOCACHE cached value ("immutable" view): NOCACHE access (unfiltered): 100 unficalllog: [100, 100] cached value (unfiltered): 100 cached value ("visible" view): NOCACHE cached value ("immutable" view): NOCACHE