)]}'
{
  "commit": "e0887c19b2daa140f20ca8104bdc5740f39dbb86",
  "tree": "86330414eb04b5989e68661c205aa52d46ca7ebf",
  "parents": [
    "21ee9f398be209ccbb62929d35961ca1ed48eec3"
  ],
  "author": {
    "name": "Rik van Riel",
    "email": "riel@redhat.com",
    "time": "Mon Oct 31 17:09:31 2011 -0700"
  },
  "committer": {
    "name": "Linus Torvalds",
    "email": "torvalds@linux-foundation.org",
    "time": "Mon Oct 31 17:30:50 2011 -0700"
  },
  "message": "vmscan: limit direct reclaim for higher order allocations\n\nWhen suffering from memory fragmentation due to unfreeable pages, THP page\nfaults will repeatedly try to compact memory.  Due to the unfreeable\npages, compaction fails.\n\nNeedless to say, at that point page reclaim also fails to create free\ncontiguous 2MB areas.  However, that doesn\u0027t stop the current code from\ntrying, over and over again, and freeing a minimum of 4MB (2UL \u003c\u003c\nsc-\u003eorder pages) at every single invocation.\n\nThis resulted in my 12GB system having 2-3GB free memory, a corresponding\namount of used swap and very sluggish response times.\n\nThis can be avoided by having the direct reclaim code not reclaim from\nzones that already have plenty of free memory available for compaction.\n\nIf compaction still fails due to unmovable memory, doing additional\nreclaim will only hurt the system, not help.\n\n[jweiner@redhat.com: change comment to explain the order check]\nSigned-off-by: Rik van Riel \u003criel@redhat.com\u003e\nAcked-by: Johannes Weiner \u003cjweiner@redhat.com\u003e\nAcked-by: Mel Gorman \u003cmgorman@suse.de\u003e\nCc: Andrea Arcangeli \u003caarcange@redhat.com\u003e\nReviewed-by: Minchan Kim \u003cminchan.kim@gmail.com\u003e\nSigned-off-by: Johannes Weiner \u003cjweiner@redhat.com\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": "f51a33e8ed89111089b35dee6b3a6f7d084b07e7",
      "old_mode": 33188,
      "old_path": "mm/vmscan.c",
      "new_id": "7e0f0579738889c092d00834519cabe0b552a527",
      "new_mode": 33188,
      "new_path": "mm/vmscan.c"
    }
  ]
}