similar: get rid of quadratic addedfiles.remove() Instead, build a set of files to be removed and recreate addedfiles only if necessary. Benchmark with 50k added/removed files, on tmpfs: $ hg addremove --dry-run --time -q original: real 16.550 secs (user 15.000+0.000 sys 1.540+0.000) previous: real 16.730 secs (user 15.280+0.000 sys 1.440+0.000) this patch: real 16.070 secs (user 14.470+0.000 sys 1.580+0.000)

#require execbit

  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ chmod 644 foo
  $ hg ci -qAm '644'

  $ chmod 755 foo
  $ hg ci -qAm '755'

reverting to rev 0

  $ hg revert -a -r 0
  reverting foo
  $ hg st
  M foo
  $ hg diff --git
  diff --git a/foo b/foo
  old mode 100755
  new mode 100644

  $ cd ..