)]}'
{
  "commit": "99bd5e2f245d8cd17d040c82d40becdb3efd9b69",
  "tree": "9dbfd8d1a9148bad45e5c3c067a05f414134083b",
  "parents": [
    "669c55e9f99b90e46eaa0f98a67ec53d46dc969a"
  ],
  "author": {
    "name": "Suresh Siddha",
    "email": "suresh.b.siddha@intel.com",
    "time": "Wed Mar 31 16:47:45 2010 -0700"
  },
  "committer": {
    "name": "Ingo Molnar",
    "email": "mingo@elte.hu",
    "time": "Fri Apr 23 11:02:02 2010 +0200"
  },
  "message": "sched: Fix select_idle_sibling() logic in select_task_rq_fair()\n\nIssues in the current select_idle_sibling() logic in select_task_rq_fair()\nin the context of a task wake-up:\n\na) Once we select the idle sibling, we use that domain (spanning the cpu that\n   the task is currently woken-up and the idle sibling that we found) in our\n   wake_affine() decisions. This domain is completely different from the\n   domain(we are supposed to use) that spans the cpu that the task currently\n   woken-up and the cpu where the task previously ran.\n\nb) We do select_idle_sibling() check only for the cpu that the task is\n   currently woken-up on. If select_task_rq_fair() selects the previously run\n   cpu for waking the task, doing a select_idle_sibling() check\n   for that cpu also helps and we don\u0027t do this currently.\n\nc) In the scenarios where the cpu that the task is woken-up is busy but\n   with its HT siblings are idle, we are selecting the task be woken-up\n   on the idle HT sibling instead of a core that it previously ran\n   and currently completely idle. i.e., we are not taking decisions based on\n   wake_affine() but directly selecting an idle sibling that can cause\n   an imbalance at the SMT/MC level which will be later corrected by the\n   periodic load balancer.\n\nFix this by first going through the load imbalance calculations using\nwake_affine() and once we make a decision of woken-up cpu vs previously-ran cpu,\nthen choose a possible idle sibling for waking up the task on.\n\nSigned-off-by: Suresh Siddha \u003csuresh.b.siddha@intel.com\u003e\nSigned-off-by: Peter Zijlstra \u003ca.p.zijlstra@chello.nl\u003e\nLKML-Reference: \u003c1270079265.7835.8.camel@sbs-t61.sc.intel.com\u003e\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "0a413c7e3ab887c53d360329609becf0915db555",
      "old_mode": 33188,
      "old_path": "kernel/sched_fair.c",
      "new_id": "cbd8b8a296d11906b8f626c25c026eafa9d03d79",
      "new_mode": 33188,
      "new_path": "kernel/sched_fair.c"
    }
  ]
}