view tests/test-mq-qpush-fail.t @ 51681:522b4d729e89

mmap: populate the mapping by default

Without pre-population, accessing all data through a mmap can result in many
pagefault, reducing performance significantly. If the mmap is prepopulated, the
performance can no longer get slower than a full read.
(See benchmark number below)

In some cases were very few data is read, prepopulating can be overkill and
slower than populating on access (through page fault). So that behavior can be
controlled when the caller can pre-determine the best behavior.
(See benchmark number below)

In addition, testing with populating in a secondary thread yield great result
combining the best of each approach. This might be implemented in later
changesets.

In all cases, using mmap has a great effect on memory usage when many processes
run in parallel on the same machine.

### Benchmarks

# What did I run

A couple of month back I ran a large benchmark campaign to assess the impact of
various approach for using mmap with the revlog (and other files), it
highlighted a few benchmarks that capture the impact of the changes well. So to
validate this change I checked the following:

- log command displaying various revisions
  (read the changelog index)
- log command displaying the patch of listed revisions
  (read the changelog index, the manifest index and a few files indexes)
- unbundling a few revisions
  (read and write changelog, manifest and few files indexes, and walk the graph
  to update some cache)
- pushing a few revisions
  (read and write changelog, manifest and few files indexes, walk the graph to
  update some cache, performs various accesses locally and remotely during
  discovery)

Benchmarks were run using the default module policy (c+py) and the rust one. No
significant difference were found between the two implementation, so we will
present result using the default policy (unless otherwise specified).

I ran them on a few repositories :

- mercurial: a "public changeset only" copy of mercurial from 2018-08-01 using
  zstd compression and sparse-revlog

- pypy: a copy of pypy from 2018-08-01 using zstd compression and sparse-revlog

- netbeans: a copy of netbeans from 2018-08-01 using zstd compression and
  sparse-revlog

- mozilla-try: a copy of mozilla-try from 2019-02-18 using zstd compression and
  sparse-revlog

- mozilla-try persistent-nodemap: Same as the above but with a persistent
  nodemap. Used for the log --patch benchmark only

# Results

For the smaller repositories (mercurial, pypy), the impact of mmap is almost
imperceptible, other cost dominating the operation. The impact of prepopulating
is undiscernible in the benchmark we ran.

For larger repositories the benchmark support explanation given above:

On netbeans, the log can be about 1% faster without repopulation (for a
difference < 100ms) but unbundle becomes a bit slower, even when small.

### data-env-vars.name                             = netbeans-2018-08-01-zstd-sparse-revlog
  # benchmark.name                                 = hg.command.unbundle
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
  # benchmark.variants.source                      = unbundle
  # benchmark.variants.verbosity                   = quiet
with-populate: 0.240157
no-populate:   0.265087  (+10.38%, +0.02)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 1.459518
no-populate:   1.481290   (+1.49%, +0.02)
 ## benchmark.name                                 = hg.command.push
  # 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
with-populate: 0.771919
no-populate:   0.792025   (+2.60%, +0.02)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 1.459518
no-populate:   1.481290   (+1.49%, +0.02)


For mozilla-try, the "slow down" from pre-populate for small `hg log` is more
visible, but still small in absolute time. (using rust value for the persistent
nodemap value to be relevant).

### data-env-vars.name            = mozilla-try-2019-02-18-ds2-pnm
  # benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # benchmark.variants.patch      = yes
  # benchmark.variants.limit-rev  = 1
with-populate: 0.237813
no-populate:   0.229452   (-3.52%, -0.01)
  # benchmark.variants.limit-rev  = 10
  # benchmark.variants.patch      = yes
with-populate: 1.213578
no-populate:   1.205189
### data-env-vars.name            = mozilla-try-2019-02-18-zstd-sparse-revlog
  # benchmark.variants.limit-rev  = 1000
  # benchmark.variants.patch      = no
  # benchmark.variants.rev        = tip
with-populate: 0.198607
no-populate:   0.195038   (-1.80%, -0.00)

However pre-populating provide a significant boost on more complex operations
like unbundle or push:

### data-env-vars.name                             = mozilla-try-2019-02-18-zstd-sparse-revlog
  # benchmark.name                                 = hg.command.push
  # 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
with-populate: 4.798632
no-populate:   4.953295   (+3.22%, +0.15)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 4.903618
no-populate:   5.014963   (+2.27%, +0.11)
 ## benchmark.name                                 = hg.command.unbundle
  # benchmark.variants.revs                        = any-1-extra-rev
with-populate: 1.423411
no-populate:   1.585365  (+11.38%, +0.16)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 1.537909
no-populate:   1.688489   (+9.79%, +0.15)

Test that qpush cleans things up if it doesn't complete

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH
  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ hg ci -Am 'add foo'
  adding foo
  $ touch untracked-file
  $ echo 'syntax: glob' > .hgignore
  $ echo '.hgignore' >> .hgignore
  $ hg qinit

test qpush on empty series

  $ hg qpush
  no patches in series
  $ hg qnew patch1
  $ echo >> foo
  $ hg qrefresh -m 'patch 1'
  $ hg qnew patch2
  $ echo bar > bar
  $ hg add bar
  $ hg qrefresh -m 'patch 2'
  $ hg qnew --config 'mq.plain=true' -U bad-patch
  $ echo >> foo
  $ hg qrefresh
  $ hg qpop -a
  popping bad-patch
  popping patch2
  popping patch1
  patch queue now empty
  $ "$PYTHON" -c 'import sys; getattr(sys.stdout, "buffer", sys.stdout).write(b"\xe9\n")' > message
  $ cat .hg/patches/bad-patch >> message
  $ mv message .hg/patches/bad-patch
  $ cat > $TESTTMP/wrapplayback.py <<EOF
  > import os
  > from mercurial import extensions, transaction
  > def wrapplayback(orig,
  >                  journal, report, opener, vfsmap, entries, backupentries,
  >                  unlink=True, checkambigfiles=None):
  >     orig(journal, report, opener, vfsmap, entries, backupentries, unlink,
  >          checkambigfiles)
  >     # Touching files truncated at "transaction.abort" causes
  >     # forcible re-loading invalidated filecache properties
  >     # (including repo.changelog)
  >     for f, o in entries:
  >         if o or not unlink:
  >             os.utime(opener.join(f), (0.0, 0.0))
  > def extsetup(ui):
  >     extensions.wrapfunction(transaction, '_playback', wrapplayback)
  > EOF
  $ hg qpush -a --config extensions.wrapplayback=$TESTTMP/wrapplayback.py  && echo 'qpush succeeded?!'
  applying patch1
  applying patch2
  applying bad-patch
  transaction abort!
  rollback completed
  cleaning up working directory...
  reverting foo
  done
  abort: decoding near '\xe9': 'ascii' codec can't decode byte 0xe9 in position 0: ordinal not in range(128)! (esc)
  [255]
  $ hg parents
  changeset:   0:bbd179dfa0a7
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo
  

test corrupt status file
  $ hg qpush
  applying patch1
  now at: patch1
  $ cp .hg/patches/status .hg/patches/status.orig
  $ hg qpop
  popping patch1
  patch queue now empty
  $ cp .hg/patches/status.orig .hg/patches/status
  $ hg qpush
  abort: working directory revision is not qtip
  [255]
  $ rm .hg/patches/status .hg/patches/status.orig


bar should be gone; other unknown/ignored files should still be around

  $ hg status -A
  ? untracked-file
  I .hgignore
  C foo

preparing qpush of a missing patch

  $ hg qpop -a
  no patches applied
  $ hg qpush
  applying patch1
  now at: patch1
  $ rm .hg/patches/patch2

now we expect the push to fail, but it should NOT complain about patch1

  $ hg qpush
  applying patch2
  unable to read patch2
  now at: patch1
  [1]

preparing qpush of missing patch with no patch applied

  $ hg qpop -a
  popping patch1
  patch queue now empty
  $ rm .hg/patches/patch1

qpush should fail the same way as below

  $ hg qpush
  applying patch1
  unable to read patch1
  [1]

Test qpush to a patch below the currently applied patch.

  $ hg qq -c guardedseriesorder
  $ hg qnew a
  $ hg qguard +block
  $ hg qnew b
  $ hg qnew c

  $ hg qpop -a
  popping c
  popping b
  popping a
  patch queue now empty

try to push and pop while a is guarded

  $ hg qpush a
  cannot push 'a' - guarded by '+block'
  [1]
  $ hg qpush -a
  applying b
  patch b is empty
  applying c
  patch c is empty
  now at: c

now try it when a is unguarded, and we're at the top of the queue

  $ hg qapplied -v
  0 G a
  1 A b
  2 A c
  $ hg qsel block
  $ hg qpush b
  abort: cannot push to a previous patch: b
  [255]
  $ hg qpush a
  abort: cannot push to a previous patch: a
  [255]

and now we try it one more time with a unguarded, while we're not at the top of the queue

  $ hg qpop b
  popping c
  now at: b
  $ hg qpush a
  abort: cannot push to a previous patch: a
  [255]

test qpop --force and backup files

  $ hg qpop -a
  popping b
  patch queue now empty
  $ hg qq --create force
  $ echo a > a
  $ echo b > b
  $ echo c > c
  $ hg ci -Am add a b c
  $ echo a >> a
  $ hg rm b
  $ hg rm c
  $ hg qnew p1
  $ echo a >> a
  $ echo bb > b
  $ hg add b
  $ echo cc > c
  $ hg add c
  $ hg qpop --force --verbose
  saving current version of a as a.orig
  saving current version of b as b.orig
  saving current version of c as c.orig
  popping p1
  patch queue now empty
  $ hg st
  ? a.orig
  ? b.orig
  ? c.orig
  ? untracked-file
  $ cat a.orig
  a
  a
  a
  $ cat b.orig
  bb
  $ cat c.orig
  cc

test qpop --force --no-backup

  $ hg qpush
  applying p1
  now at: p1
  $ rm a.orig
  $ echo a >> a
  $ hg qpop --force --no-backup --verbose
  popping p1
  patch queue now empty
  $ test -f a.orig && echo 'error: backup with --no-backup'
  [1]

test qpop --keep-changes

  $ hg qpush
  applying p1
  now at: p1
  $ hg qpop --keep-changes --force
  abort: cannot use both --force and --keep-changes
  [255]
  $ echo a >> a
  $ hg qpop --keep-changes
  abort: local changes found, qrefresh first
  [255]
  $ hg revert -qa a
  $ rm a
  $ hg qpop --keep-changes
  abort: local changes found, qrefresh first
  [255]
  $ hg rm -A a
  $ hg qpop --keep-changes
  abort: local changes found, qrefresh first
  [255]
  $ hg revert -qa a
  $ echo b > b
  $ hg add b
  $ hg qpop --keep-changes
  abort: local changes found, qrefresh first
  [255]
  $ hg forget b
  $ echo d > d
  $ hg add d
  $ hg qpop --keep-changes
  popping p1
  patch queue now empty
  $ hg forget d
  $ rm d

test qpush --force and backup files

  $ echo a >> a
  $ hg qnew p2
  $ echo b >> b
  $ echo d > d
  $ echo e > e
  $ hg add d e
  $ hg rm c
  $ hg qnew p3
  $ hg qpop -a
  popping p3
  popping p2
  patch queue now empty
  $ echo a >> a
  $ echo b1 >> b
  $ echo d1 > d
  $ hg add d
  $ echo e1 > e
  $ hg qpush -a --force --verbose
  applying p2
  saving current version of a as a.orig
  patching file a
  committing files:
  a
  committing manifest
  committing changelog
  applying p3
  saving current version of b as b.orig
  saving current version of d as d.orig
  patching file b
  patching file c
  patching file d
  file d already exists
  1 out of 1 hunks FAILED -- saving rejects to file d.rej
  patching file e
  file e already exists
  1 out of 1 hunks FAILED -- saving rejects to file e.rej
  patch failed to apply
  committing files:
  b
  committing manifest
  committing changelog
  patch failed, rejects left in working directory
  errors during apply, please fix and qrefresh p3
  [2]
  $ cat a.orig
  a
  a
  $ cat b.orig
  b
  b1
  $ cat d.orig
  d1

test qpush --force --no-backup

  $ hg revert -qa
  $ hg qpop -a
  popping p3
  popping p2
  patch queue now empty
  $ echo a >> a
  $ rm a.orig
  $ hg qpush --force --no-backup --verbose
  applying p2
  patching file a
  committing files:
  a
  committing manifest
  committing changelog
  now at: p2
  $ test -f a.orig && echo 'error: backup with --no-backup'
  [1]

test qgoto --force --no-backup

  $ hg qpop
  popping p2
  patch queue now empty
  $ echo a >> a
  $ hg qgoto --force --no-backup p2 --verbose
  applying p2
  patching file a
  committing files:
  a
  committing manifest
  committing changelog
  now at: p2
  $ test -f a.orig && echo 'error: backup with --no-backup'
  [1]

test qpush --keep-changes

  $ hg qpush --keep-changes --force
  abort: cannot use both --force and --keep-changes
  [255]
  $ hg qpush --keep-changes --exact
  abort: cannot use --exact and --keep-changes together
  [255]
  $ echo b >> b
  $ hg qpush --keep-changes
  applying p3
  abort: conflicting local changes found
  (did you forget to qrefresh?)
  [255]
  $ rm b
  $ hg qpush --keep-changes
  applying p3
  abort: conflicting local changes found
  (did you forget to qrefresh?)
  [255]
  $ hg rm -A b
  $ hg qpush --keep-changes
  applying p3
  abort: conflicting local changes found
  (did you forget to qrefresh?)
  [255]
  $ hg revert -aq b
  $ echo d > d
  $ hg add d
  $ hg qpush --keep-changes
  applying p3
  abort: conflicting local changes found
  (did you forget to qrefresh?)
  [255]
  $ hg forget d
  $ rm d
  $ hg qpop
  popping p2
  patch queue now empty
  $ echo b >> b
  $ hg qpush -a --keep-changes
  applying p2
  applying p3
  abort: conflicting local changes found
  (did you forget to qrefresh?)
  [255]
  $ hg qtop
  p2
  $ hg parents --template "{rev} {desc}\n"
  2 imported patch p2
  $ hg st b
  M b
  $ cat b
  b
  b

test qgoto --keep-changes

  $ hg revert -aq b
  $ rm e
  $ hg qgoto --keep-changes --force p3
  abort: cannot use both --force and --keep-changes
  [255]
  $ echo a >> a
  $ hg qgoto --keep-changes p3
  applying p3
  now at: p3
  $ hg st a
  M a
  $ hg qgoto --keep-changes p2
  popping p3
  now at: p2
  $ hg st a
  M a

test mq.keepchanges setting

  $ hg --config mq.keepchanges=1 qpush
  applying p3
  now at: p3
  $ hg st a
  M a
  $ hg --config mq.keepchanges=1 qpop
  popping p3
  now at: p2
  $ hg st a
  M a
  $ hg --config mq.keepchanges=1 qgoto p3
  applying p3
  now at: p3
  $ hg st a
  M a
  $ echo b >> b
  $ hg --config mq.keepchanges=1 qpop --force --config 'ui.origbackuppath=.hg/origbackups'
  popping p3
  now at: p2
  $ hg st b
  $ hg --config mq.keepchanges=1 qpush --exact
  abort: local changes found, qrefresh first
  [255]
  $ hg revert -qa a
  $ hg qpop
  popping p2
  patch queue now empty
  $ echo a >> a
  $ hg --config mq.keepchanges=1 qpush --force
  applying p2
  now at: p2
  $ hg st a

test previous qpop (with --force and --config) saved .orig files to where user
wants them
  $ ls .hg/origbackups
  b
  $ rm -rf .hg/origbackups

  $ cd ..