[darcs-users] optimization in HEAD: darcs diff

[Guillaume Hoffmann]

A few memory allocation figures obtained with "+RTS -s" for two cases
(recent patch and old patch):

* patch "kill footnotes" (latest):

2.8
     287,535,128 bytes allocated in the heap
      59,356,640 bytes copied during GC
      14,969,680 bytes maximum residency (9 sample(s))
         342,752 bytes maximum slop
              32 MB total memory in use (0 MB lost due to fragmentation)
[..]
  %GC time      17.5%  (16.5% elapsed)
  Alloc rate    871,318,569 bytes per MUT second
  Productivity  82.5% of total user, 59.8% of total elapsed

HEAD
      62,756,136 bytes allocated in the heap
      37,237,544 bytes copied during GC
      12,593,440 bytes maximum residency (6 sample(s))
         332,928 bytes maximum slop
              24 MB total memory in use (0 MB lost due to fragmentation)
[..]
  %GC time       0.0%  (38.1% elapsed)
  Alloc rate    697,290,400 bytes per MUT second
  Productivity 100.0% of total user, 64.1% of total elapsed

* patch "Import bracketOnError from Workaound" from 2006:

2.8
  17,413,824,480 bytes allocated in the heap
   1,306,485,280 bytes copied during GC
      10,460,976 bytes maximum residency (173 sample(s))
       1,761,112 bytes maximum slop
              30 MB total memory in use (0 MB lost due to fragmentation)
[..]
  %GC time       7.4%  (3.3% elapsed)
  Alloc rate    1,225,462,665 bytes per MUT second
  Productivity  92.6% of total user, 18.8% of total elapsed

HEAD
  14,516,729,880 bytes allocated in the heap
   1,906,137,160 bytes copied during GC
     174,140,552 bytes maximum residency (20 sample(s))
      26,304,952 bytes maximum slop
             430 MB total memory in use (0 MB lost due to fragmentation)
[..]
  %GC time      26.7%  (34.7% elapsed)
  Alloc rate    1,131,467,644 bytes per MUT second
  Productivity  73.3% of total user, 71.6% of total elapsed