)]}'
{
  "commit": "02bf60aad7d5912dfcdbe0154f1bd67ea7a8301e",
  "tree": "4d0c009e30079b127e0d7b01cdd30d8375e44c7c",
  "parents": [
    "11d232ec285b07860670277c8ab3f6076f7bce1e"
  ],
  "author": {
    "name": "Anton Blanchard",
    "email": "anton@samba.org",
    "time": "Tue May 04 21:19:15 2010 +1000"
  },
  "committer": {
    "name": "Arnaldo Carvalho de Melo",
    "email": "acme@redhat.com",
    "time": "Tue May 04 10:54:09 2010 -0300"
  },
  "message": "perf: Fix performance issue with perf report\n\nOn a large machine we spend a lot of time in perf_header__find_attr when\nrunning perf report.\n\nIf we are parsing a file without PERF_SAMPLE_ID then for each sample we call\nperf_header__find_attr and loop through all counter IDs, never finding a match.\nAs the machine gets larger there are more per cpu counters and we spend an\nawful lot of time in there.\n\nThe patch below initialises each sample id to -1ULL and checks for this in\nperf_header__find_attr. We may need to do something more intelligent eventually\n(eg a hash lookup from counter id to attr) but this at least fixes the most\ncommon usage of perf report.\n\nCc: Peter Zijlstra \u003ca.p.zijlstra@chello.nl\u003e\nCc: Paul Mackerras \u003cpaulus@samba.org\u003e\nCc: Ingo Molnar \u003cmingo@elte.hu\u003e\nCc: Frederic Weisbecker \u003cfweisbec@gmail.com\u003e\nCc: Eric B Munson \u003cebmunson@us.ibm.com\u003e\nAcked-by: Eric B Munson \u003cebmunson@us.ibm.com\u003e\nLKML-Reference: \u003c20100504111915.GB14636@kryten\u003e\nSigned-off-by: Anton Blanchard \u003canton@samba.org\u003e\n--\nSigned-off-by: Arnaldo Carvalho de Melo \u003cacme@redhat.com\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "1757b0ffeaa97a29812b4727d451305110c9ba3f",
      "old_mode": 33188,
      "old_path": "tools/perf/util/event.c",
      "new_id": "2477270c1d3fe372dcdb6cf840356a2e3846a8fd",
      "new_mode": 33188,
      "new_path": "tools/perf/util/event.c"
    },
    {
      "type": "modify",
      "old_id": "2b9f898efea6479290018d3aa7c6339586d4b45f",
      "old_mode": 33188,
      "old_path": "tools/perf/util/header.c",
      "new_id": "8847bec64c54119fc0e006dbd6350b231203dbd9",
      "new_mode": 33188,
      "new_path": "tools/perf/util/header.c"
    }
  ]
}