.hgignore

revlog: use mmap by default is pre-population is available

Using mmap has a great impact of memory usage on server, and a good impact on
performance in multiple case. Now that we pre-populate memory mapping by
default, there is case where it using mmap is slower. So we use it by default
(if pre-population is available).

Further work to reduce the performance impact of the pre-population will be done
later.

Some benchmark below (using the same setup as 522b4d729e89):

As for 522b4d729e89 the impact on small repository like Mercurial or Pypy is
tiny, ~1% best. However for large repositories we see some performance
improvement without seeing the performance regression that we could have without
pre-populate.

##### For netbeans

### data-env-vars.name            = netbeans-2018-08-01-zstd-sparse-revlog
 ## benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # benchmark.variants.limit-rev  = 1
  # benchmark.variants.patch      = yes
no-mmap:     0.171579
mmap:        0.166311   (-3.07%, -0.01)
  # bin-env-vars.hg.flavor        = default
no-mmap:     0.170716
mmap:        0.165218   (-3.22%, -0.01)
  # benchmark.variants.patch      = no
  # benchmark.variants.rev        = tip
no-mmap:     0.140862
mmap:        0.137566   (-2.34%, -0.00)
 ## benchmark.name                                 = hg.command.unbundle
  # bin-env-vars.hg.flavor                         = rust
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
  # benchmark.variants.source                      = unbundle
no-mmap:     0.238038
mmap:        0.239912
no-populate: 0.cbd4c9  (+11.71%, +0.03)


#### For Mozilla

### data-env-vars.name            = mozilla-try-2019-02-18-ds2-pnm
  # benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.limit-rev  = 1
  # benchmark.variants.patch      = yes
no-mmap:     0.258440
mmap:        0.237813   (-7.98%, -0.02)
  # benchmark.variants.limit-rev  = 10
no-mmap:     1.235323
mmap:        1.213578   (-1.76%, -0.02)
 ## benchmark.name                                 = hg.command.push
  # bin-env-vars.hg.flavor                         = rust
  # bin-env-vars.hg.py-re2-module                  = default
  # benchmark.variants.explicit-rev                = none
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.protocol                    = ssh
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
no-mmap:     4.790135
mmap:        4.668971   (-2.53%, -0.12)
no-populate: 4.841141   (+1.06%, +0.05)


### data-env-vars.name            = mozilla-try-2019-02-18-zstd-sparse-revlog
 ## benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = default
  # benchmark.variants.limit-rev  = 1000
  # benchmark.variants.rev        = tip
no-mmap:     0.206187
mmap:        0.197348   (-4.29%, -0.01)
 ## benchmark.name                                 = hg.command.push
  # bin-env-vars.hg.flavor                         = default
  # benchmark.variants.explicit-rev                = none
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.protocol                    = ssh
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
no-mmap:     4.768259
mmap:        4.798632
no-populate: 4.953295   (+3.88%, +0.19)
  # benchmark.variants.revs                        = any-100-extra-rev
no-mmap:     4.785946
mmap:        4.903618
no-populate: 5.014963   (+4.79%, +0.23)
 ## benchmark.name                                 = hg.command.unbundle
  # bin-env-vars.hg.flavor                         = default
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
  # benchmark.variants.source                      = unbundle
no-mmap:     1.400121
mmap:        1.423411
no-populate: 1.585365  (+13.23%, +0.19)

syntax: glob

*.elc
*.tmp
*.orig
*.rej
*~
*.mergebackup
*.o
*.so
*.dll
*.exe
*.pyd
*.pyc
*.pyo
*$py.class
*.swp
*.prof
*.zip
\#*\#
.\#*
result/
tests/artifacts/cache/big-file-churn.hg
tests/.coverage*
tests/.testtimes*
# the file is written in the CWD when run-tests is run.
.testtimes
tests/.hypothesis
tests/hypothesis-generated
tests/annotated
tests/exceptions
tests/python3
tests/*.err
tests/htmlcov
build
contrib/chg/chg
contrib/hgsh/hgsh
contrib/vagrant/.vagrant
contrib/merge-lists/target/
dist
packages
doc/common.txt
doc/*.[0-9]
doc/*.[0-9].txt
doc/*.[0-9].gendoc.txt
doc/*.[0-9].{x,ht}ml
MANIFEST
MANIFEST.in
patches
mercurial/__modulepolicy__.py
mercurial/__version__.py
mercurial/hgpythonlib.h
mercurial.egg-info
.DS_Store
tags
cscope.*
.vscode/*
.idea/*
.asv/*
.pytype/*
.mypy_cache
i18n/hg.pot
locale/*/LC_MESSAGES/hg.mo
hgext/__index__.py

rust/target/
rust/*/target/

# Generated wheels
wheelhouse/

syntax: rootglob
# See Profiling in rust/README.rst
.cargo/config

syntax: regexp
^\.pc/
^\.(pydev)?project

# hackable windows distribution additions
^hg-python
^hg.py$