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Re: git-diff-tree inordinately (O(M*N)) slow on files with many changes

From
Jim Meyering <jim@meyering.net>
Date
Oct 16, 2006, 16:33 UTC
Message-ID
<87mz7wp6ek.fsf@rho.meyering.net>
In-Reply-To
<Pine.LNX.4.64.0610160904400.3962@g5.osdl.org>
Linus Torvalds <torvalds@osdl.org> wrote:
> On Mon, 16 Oct 2006, Linus Torvalds wrote:
...
> So I think xdiff has chosen too small a hash. Can you try what happens if
> you change xdl_hashbits() (in xdiff/xutil.c) instead? Try making it return
> a bigger value (for example, by initializing "bits" to 2 instead of 0),
> and see if that makes a difference.
It makes no difference.

Bear in mind that there are a *lot* of duplicate lines in the files being compared: filtering each through "sort -u" removes 40-50k lines.

Previous: Linus TorvaldsNext: Davide Libenzi
Message 4 of 27 in “git-diff-tree inordinately (O(M*N)) slow on files with many changes”
  1. Jim MeyeringOct 16, 2006
  2. Linus TorvaldsOct 16, 2006
  3. Linus TorvaldsOct 16, 2006
  4. Jim MeyeringOct 16, 2006
  5. Davide LibenziOct 16, 2006
  6. Jim MeyeringOct 16, 2006
  7. Davide LibenziOct 16, 2006
  8. Jim MeyeringOct 16, 2006
  9. Davide LibenziOct 16, 2006
  10. Linus TorvaldsOct 16, 2006
  11. Linus TorvaldsOct 16, 2006
  12. Davide LibenziOct 16, 2006
  13. Davide LibenziOct 16, 2006
  14. Linus TorvaldsOct 16, 2006
  15. Davide LibenziOct 16, 2006
  16. Jakub NarebskiOct 16, 2006
  17. Junio C HamanoOct 16, 2006
  18. Linus TorvaldsOct 16, 2006
  19. Davide LibenziOct 16, 2006
  20. Jim MeyeringOct 16, 2006
  21. Davide LibenziOct 16, 2006
  22. Jim MeyeringOct 16, 2006
  23. Linus TorvaldsOct 16, 2006
  24. Davide LibenziOct 16, 2006
  25. Linus TorvaldsOct 16, 2006
  26. Davide LibenziOct 16, 2006
  27. Jakub NarebskiOct 16, 2006

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