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Re: Performance issue of 'git branch'

From
CMCarlos R. Mafra <crmafra2@gmail.com>
Date
Jul 23, 2009, 16:07 UTC
Message-ID
<20090723160740.GA5736@Pilar.aei.mpg.de>
In-Reply-To
<7vtz146mgr.fsf@alter.siamese.dyndns.org>
On Wed 22.Jul'09 at 21:40:36 -0700, Junio C Hamano wrote:
> Is the cold cache performance of "git branch" to list your 
> local branches that important?

I simply felt like something not optimal was going on, and in some sense I still feel it even with Linus' patch applied...

Don't get me wrong, I am super happy that Linus fixed it so quickly and I am grateful for that, but I am surely missing some git internal reason why 'git branch' is not instantaneous as I _naively_ expected.

Having learned about .git/packed-refs last night, today I tried this (with cold cache),

[mafra@Pilar:linux-2.6]$ time awk '{print $2}' .git/packed-refs |grep heads| awk -F "/" '{print $3}' 0.00user 0.00system 0:00.12elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (3major+311minor)pagefaults 0swaps 27-stable 28-stable 29-stable 30-stable dev-private master option sparse stern

and notice how that makes my pitiful harddisc look like Linus' SSD! And the result is the same.

[ If some branches are not inside .git/packed-refs but are listed in .git/refs/heads (like some of them were last night), it would require some modification to the script, but it would still be faster ]

However, I know that I am missing something here and I would be happy to learn what.

Thanks in advance, Carlos

Previous: Linus TorvaldsNext: Linus Torvalds
Message 33 of 73 in “Performance issue of 'git branch'”
  1. Carlos R. MafraJul 22, 2009
  2. Linus TorvaldsJul 23, 2009
  3. Linus TorvaldsJul 23, 2009
  4. Linus TorvaldsJul 23, 2009
  5. Carlos R. MafraJul 23, 2009
  6. Linus TorvaldsJul 23, 2009
  7. Jakub NarebskiJul 23, 2009
  8. Carlos R. MafraJul 23, 2009
  9. Linus TorvaldsJul 23, 2009
  10. Carlos R. MafraJul 23, 2009
  11. Linus TorvaldsJul 23, 2009
  12. Linus TorvaldsJul 23, 2009
  13. Linus TorvaldsJul 23, 2009
  14. Linus TorvaldsJul 23, 2009
  15. Tony FinchJul 23, 2009
  16. Linus TorvaldsJul 23, 2009
  17. Newton-Raphson, was Re: Performance issue of 'git branch'Tony Finch, Jul 23, 2009
  18. Johannes SchindelinJul 23, 2009
  19. Tony FinchJul 23, 2009
  20. Johannes SchindelinJul 24, 2009
  21. Carlos R. MafraJul 23, 2009
  22. Carlos R. MafraJul 23, 2009
  23. Carlos R. MafraJul 23, 2009
  24. Linus TorvaldsJul 23, 2009
  25. Linus TorvaldsJul 23, 2009
  26. Junio C HamanoJul 23, 2009
  27. Carlos R. MafraJul 23, 2009
  28. Junio C HamanoJul 23, 2009
  29. Linus TorvaldsJul 23, 2009
  30. Junio C HamanoJul 23, 2009
  31. Junio C HamanoJul 23, 2009
  32. Linus TorvaldsJul 23, 2009
  33. Carlos R. MafraJul 23, 2009
  34. Linus TorvaldsJul 23, 2009
  35. Carlos R. MafraJul 23, 2009
  36. Linus TorvaldsJul 23, 2009
  37. Linus TorvaldsJul 23, 2009
  38. Carlos R. MafraJul 23, 2009
  39. Linus TorvaldsJul 24, 2009
  40. Linus TorvaldsJul 24, 2009
  41. Linus TorvaldsJul 24, 2009
  42. Linus TorvaldsJul 24, 2009
  43. david@lang.hmJul 24, 2009
  44. Linus TorvaldsJul 24, 2009
  45. david@lang.hmJul 24, 2009
  46. Linus TorvaldsJul 25, 2009
  47. Daniel BarkalowJul 25, 2009
  48. Jeff KingAug 7, 2009
  49. Theodore TsoJul 24, 2009
  50. Shawn O. PearceJul 24, 2009
  51. Junio C HamanoJul 24, 2009
  52. Avi KivityJul 26, 2009
  53. Johannes SchindelinJul 26, 2009
  54. Carlos R. MafraJul 24, 2009
  55. Carlos R. MafraJul 25, 2009
  56. Linus TorvaldsJul 25, 2009
  57. Timo HirvonenJul 25, 2009
  58. Reece DunnJul 25, 2009
  59. Mike HommeyJul 25, 2009
  60. Linus TorvaldsJul 25, 2009
  61. Linus TorvaldsJul 25, 2009
  62. Johannes SchindelinJul 25, 2009
  63. Linus TorvaldsJul 26, 2009
  64. Theodore TsoJul 26, 2009
  65. Mike HommeyJul 26, 2009
  66. Johannes SchindelinJul 26, 2009
  67. demerphqJul 26, 2009
  68. demerphqJul 26, 2009
  69. Carlos R. MafraJul 25, 2009
  70. Anders KaseorgJul 23, 2009
  71. Carlos R. MafraJul 23, 2009
  72. SZEDER GáborJul 23, 2009
  73. Carlos R. MafraJul 23, 2009

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