)]}'
{
  "commit": "2accfdb7eff65f390c4308b0e9cb7c3fe48ad63c",
  "tree": "17eadc8c40ec82aab8c46932191d7af39d2469d1",
  "parents": [
    "7c51f7bbf057f82aeba3390c39ef61b244181c09"
  ],
  "author": {
    "name": "Linus Torvalds",
    "email": "torvalds@linux-foundation.org",
    "time": "Mon Jul 29 10:58:28 2024 -0700"
  },
  "committer": {
    "name": "Linus Torvalds",
    "email": "torvalds@linux-foundation.org",
    "time": "Mon Jul 29 10:58:28 2024 -0700"
  },
  "message": "profiling: attempt to remove per-cpu profile flip buffer\n\nThis is the really old legacy kernel profiling code, which has long\nsince been obviated by \"real profiling\" (ie \u0027prof\u0027 and company), and\nmainly remains as a source of syzbot reports.\n\nThere are anecdotal reports that people still use it for boot-time\nprofiling, but it\u0027s unlikely that such use would care about the old NUMA\noptimizations in this code from 2004 (commit ad02973d42: \"profile: 512x\nAltix timer interrupt livelock fix\" in the BK import archive at [1])\n\nSo in order to head off future syzbot reports, let\u0027s try to simplify\nthis code and get rid of the per-cpu profile buffers that are quite a\nlarge portion of the complexity footprint of this thing (including CPU\nhotplug callbacks etc).\n\nIt\u0027s unlikely anybody will actually notice, or possibly, as Thomas put\nit: \"Only people who indulge in nostalgia will notice :)\".\n\nThat said, if it turns out that this code is actually actively used by\nsomebody, we can always revert this removal.  Thus the \"attempt\" in the\nsummary line.\n\n[ Note: in a small nod to \"the profiling code can cause NUMA problems\",\n  this also removes the \"increment the last entry in the profiling array\n  on any unknown hits\" logic. That would account any program counter in\n  a module to that single counter location, and might exacerbate any\n  NUMA cacheline bouncing issues ]\n\nLink: https://lore.kernel.org/all/CAHk-\u003dwgs52BxT4Zjmjz8aNvHWKxf5_ThBY4bYL1Y6CTaNL2dTw@mail.gmail.com/\nLink:  https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git [1]\nCc: Thomas Gleixner \u003ctglx@linutronix.de\u003e\nCc: Tetsuo Handa \u003cpenguin-kernel@i-love.sakura.ne.jp\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "51ba681b915a979e5475eecf3fc89c71623b3af6",
      "old_mode": 33188,
      "old_path": "include/linux/cpuhotplug.h",
      "new_id": "affdd890899ecf17fcb32cac22bd5e76863d8d09",
      "new_mode": 33188,
      "new_path": "include/linux/cpuhotplug.h"
    },
    {
      "type": "modify",
      "old_id": "4654c6cd984e4cc761c467e5ee5df57a15d83ebc",
      "old_mode": 33188,
      "old_path": "kernel/profile.c",
      "new_id": "2dfb0f4e755c5fbd51ad4985243d5badc548758d",
      "new_mode": 33188,
      "new_path": "kernel/profile.c"
    }
  ]
}