)]}'
{
  "commit": "661f627da98c0647bcc002ef35e5441fb3ce667c",
  "tree": "0820ff0d1734edb252c0073babf7806614a8fa55",
  "parents": [
    "789f0f89118a80a3ff5309371e5820f623ed2a53"
  ],
  "author": {
    "name": "Arnd Bergmann",
    "email": "arnd@arndb.de",
    "time": "Thu Nov 05 19:52:55 2009 +0100"
  },
  "committer": {
    "name": "Arnd Bergmann",
    "email": "arnd@arndb.de",
    "time": "Thu Dec 10 22:52:11 2009 +0100"
  },
  "message": "compat_ioctl: simplify lookup table\n\nThe compat_ioctl table now only contains entries for\nCOMPATIBLE_IOCTL, so we only need to know if a number\nis listed in it or now.\n\nAs an optimization, we hash the table entries with a\nreversible transformation to get a more uniform distribution\nover it, sort the table at startup and then guess the\nposition in the table when an ioctl number gets called\nto do a linear search from there.\n\nWith the current set of ioctl numbers and the chosen\ntransformation function, we need an average of four\nsteps to find if a number is in the set, all of the\naccesses within one or two cache lines.\n\nThis at least as good as the previous hash table\napproach but saves 8.5 kb of kernel memory.\n\nSigned-off-by: Arnd Bergmann \u003carnd@arndb.de\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "7895bdb0c30444f935391b13eeb3300a1963c508",
      "old_mode": 33188,
      "old_path": "fs/compat_ioctl.c",
      "new_id": "b4873ae84ca1c68a6e0fac214e2401c4d523f4bb",
      "new_mode": 33188,
      "new_path": "fs/compat_ioctl.c"
    }
  ]
}