)]}'
{
  "commit": "ca0984caa8235762dc4e22c1c47ae6719dcc4064",
  "tree": "6c59dae501f781e970d81d60580cf52542356a09",
  "parents": [
    "2149cdaef6c0eb59a9edf3b152027392cd66b41f"
  ],
  "author": {
    "name": "Ebru Akagunduz",
    "email": "ebru.akagunduz@gmail.com",
    "time": "Tue Apr 14 15:45:24 2015 -0700"
  },
  "committer": {
    "name": "Linus Torvalds",
    "email": "torvalds@linux-foundation.org",
    "time": "Tue Apr 14 16:49:01 2015 -0700"
  },
  "message": "mm: incorporate zero pages into transparent huge pages\n\nThis patch improves THP collapse rates, by allowing zero pages.\n\nCurrently THP can collapse 4kB pages into a THP when there are up to\nkhugepaged_max_ptes_none pte_none ptes in a 2MB range.  This patch counts\npte none and mapped zero pages with the same variable.\n\nThe patch was tested with a program that allocates 800MB of\nmemory, and performs interleaved reads and writes, in a pattern\nthat causes some 2MB areas to first see read accesses, resulting\nin the zero pfn being mapped there.\n\nTo simulate memory fragmentation at allocation time, I modified\ndo_huge_pmd_anonymous_page to return VM_FAULT_FALLBACK for read faults.\n\nWithout the patch, only %50 of the program was collapsed into THP and the\npercentage did not increase over time.\n\nWith this patch after 10 minutes of waiting khugepaged had collapsed %99\nof the program\u0027s memory.\n\n[aarcange@redhat.com: fix bogus BUG()]\nSigned-off-by: Ebru Akagunduz \u003cebru.akagunduz@gmail.com\u003e\nReviewed-by: Rik van Riel \u003criel@redhat.com\u003e\nReviewed-by: Andrea Arcangeli \u003caarcange@redhat.com\u003e\nAcked-by: Kirill A. Shutemov \u003ckirill.shutemov@linux.intel.com\u003e\nAcked-by: Vlastimil Babka \u003cvbabka@suse.cz\u003e\nCc: Hugh Dickins \u003chughd@google.com\u003e\nCc: Johannes Weiner \u003channes@cmpxchg.org\u003e\nCc: Sasha Levin \u003csasha.levin@oracle.com\u003e\nCc: David Rientjes \u003crientjes@google.com\u003e\nCc: Mel Gorman \u003cmel@csn.ul.ie\u003e\nSigned-off-by: Andrea Arcangeli \u003caarcange@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": "10a4b6cea0d10a27f3792b8a61f1a415b911f9a0",
      "old_mode": 33188,
      "old_path": "mm/huge_memory.c",
      "new_id": "6352c1dfa898385e545ad76c179b882da884046f",
      "new_mode": 33188,
      "new_path": "mm/huge_memory.c"
    }
  ]
}