)]}'
{
  "commit": "1306d603fcf1f6682f8575d1ff23631a24184b21",
  "tree": "8e2278cfabf874cb16bf03bd182ae75b87055741",
  "parents": [
    "f146aabfe921006b98dfa4a78506763aedfd3206"
  ],
  "author": {
    "name": "KOSAKI Motohiro",
    "email": "kosaki.motohiro@jp.fujitsu.com",
    "time": "Fri Jan 08 14:42:56 2010 -0800"
  },
  "committer": {
    "name": "Linus Torvalds",
    "email": "torvalds@linux-foundation.org",
    "time": "Mon Jan 11 09:34:06 2010 -0800"
  },
  "message": "proc: partially revert \"procfs: provide stack information for threads\"\n\nCommit d899bf7b (procfs: provide stack information for threads) introduced\nto show stack information in /proc/{pid}/status.  But it cause large\nperformance regression.  Unfortunately /proc/{pid}/status is used ps\ncommand too and ps is one of most important component.  Because both to\ntake mmap_sem and page table walk are heavily operation.\n\nIf many process run, the ps performance is,\n\n[before d899bf7b]\n\n% perf stat ps \u003e/dev/null\n\n Performance counter stats for \u0027ps\u0027:\n\n     4090.435806  task-clock-msecs         #      0.032 CPUs\n             229  context-switches         #      0.000 M/sec\n               0  CPU-migrations           #      0.000 M/sec\n             234  page-faults              #      0.000 M/sec\n      8587565207  cycles                   #   2099.425 M/sec\n      9866662403  instructions             #      1.149 IPC\n      3789415411  cache-references         #    926.409 M/sec\n        30419509  cache-misses             #      7.437 M/sec\n\n   128.859521955  seconds time elapsed\n\n[after d899bf7b]\n\n% perf stat  ps  \u003e /dev/null\n\n Performance counter stats for \u0027ps\u0027:\n\n     4305.081146  task-clock-msecs         #      0.028 CPUs\n             480  context-switches         #      0.000 M/sec\n               2  CPU-migrations           #      0.000 M/sec\n             237  page-faults              #      0.000 M/sec\n      9021211334  cycles                   #   2095.480 M/sec\n     10605887536  instructions             #      1.176 IPC\n      3612650999  cache-references         #    839.160 M/sec\n        23917502  cache-misses             #      5.556 M/sec\n\n   152.277819582  seconds time elapsed\n\nThus, this patch revert it. Fortunately /proc/{pid}/task/{tid}/smaps\nprovide almost same information. we can use it.\n\nCommit d899bf7b introduced two features:\n\n 1) Add the annotattion of [thread stack: xxxx] mark to\n    /proc/{pid}/task/{tid}/maps.\n 2) Add StackUsage field to /proc/{pid}/status.\n\nI only revert (2), because I haven\u0027t seen (1) cause regression.\n\nSigned-off-by: KOSAKI Motohiro \u003ckosaki.motohiro@jp.fujitsu.com\u003e\nCc: Stefani Seibold \u003cstefani@seibold.net\u003e\nCc: Ingo Molnar \u003cmingo@elte.hu\u003e\nCc: Peter Zijlstra \u003ca.p.zijlstra@chello.nl\u003e\nCc: Alexey Dobriyan \u003cadobriyan@gmail.com\u003e\nCc: \"Eric W. Biederman\" \u003cebiederm@xmission.com\u003e\nCc: Randy Dunlap \u003crandy.dunlap@oracle.com\u003e\nCc: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nCc: Andi Kleen \u003candi@firstfloor.org\u003e\nSigned-off-by: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "220cc6376ef80e0c9bcfec162d45552e729cdf5a",
      "old_mode": 33188,
      "old_path": "Documentation/filesystems/proc.txt",
      "new_id": "0d07513a67a661440fc1599121bb1dc38560bc33",
      "new_mode": 33188,
      "new_path": "Documentation/filesystems/proc.txt"
    },
    {
      "type": "modify",
      "old_id": "f560325c444f0c10e6258ce7c5d9836c58d703b9",
      "old_mode": 33188,
      "old_path": "fs/proc/array.c",
      "new_id": "13b5d07081751e1cb42aca4ce491c9a52b70ab4f",
      "new_mode": 33188,
      "new_path": "fs/proc/array.c"
    }
  ]
}