)]}'
{
  "commit": "dedeb0029b9c83420fc1337d4ee53daa7b2a0ad4",
  "tree": "d87e66e1d6240cd412c20ecbc12f5b810c9807e4",
  "parents": [
    "b8ae48656db860d4c83a29aa7b0588fc89361935"
  ],
  "author": {
    "name": "Hugh Dickins",
    "email": "hugh@veritas.com",
    "time": "Mon Nov 07 14:09:01 2005 -0800"
  },
  "committer": {
    "name": "David S. Miller",
    "email": "davem@davemloft.net",
    "time": "Mon Nov 07 14:09:01 2005 -0800"
  },
  "message": "[SPARC64] mm: context switch ptlock\n\nsparc64 is unique among architectures in taking the page_table_lock in\nits context switch (well, cris does too, but erroneously, and it\u0027s not\nyet SMP anyway).\n\nThis seems to be a private affair between switch_mm and activate_mm,\nusing page_table_lock as a per-mm lock, without any relation to its uses\nelsewhere.  That\u0027s fine, but comment it as such; and unlock sooner in\nswitch_mm, more like in activate_mm (preemption is disabled here).\n\nThere is a block of \"if (0)\"ed code in smp_flush_tlb_pending which would\nhave liked to rely on the page_table_lock, in switch_mm and elsewhere;\nbut its comment explains how dup_mmap\u0027s flush_tlb_mm defeated it.  And\nthough that could have been changed at any time over the past few years,\nnow the chance vanishes as we push the page_table_lock downwards, and\nperhaps split it per page table page.  Just delete that block of code.\n\nWhich leaves the mysterious spin_unlock_wait(\u0026oldmm-\u003epage_table_lock)\nin kernel/fork.c copy_mm.  Textual analysis (supported by Nick Piggin)\nsuggests that the comment was written by DaveM, and that it relates to\nthe defeated approach in the sparc64 smp_flush_tlb_pending.  Just delete\nthis block too.\n\nSigned-off-by: Hugh Dickins \u003chugh@veritas.com\u003e\nSigned-off-by: David S. Miller \u003cdavem@davemloft.net\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "b137fd63f5e12691a87c24113d8581f1e8daf45c",
      "old_mode": 33188,
      "old_path": "arch/sparc64/kernel/smp.c",
      "new_id": "a9089e2140e9950eee1b7a6ff807400b4bc26dae",
      "new_mode": 33188,
      "new_path": "arch/sparc64/kernel/smp.c"
    },
    {
      "type": "modify",
      "old_id": "87c43c67866e9bb6afbc5cdd8186d3edecdf5816",
      "old_mode": 33188,
      "old_path": "include/asm-sparc64/mmu_context.h",
      "new_id": "08ba72d7722c9c4be4fe7d96eb534ceb75d968c4",
      "new_mode": 33188,
      "new_path": "include/asm-sparc64/mmu_context.h"
    },
    {
      "type": "modify",
      "old_id": "efac2c58ec7d7eb4889b962af69b372b669640f1",
      "old_mode": 33188,
      "old_path": "kernel/fork.c",
      "new_id": "158710d22566006a36e6fbfb2583641eea24369e",
      "new_mode": 33188,
      "new_path": "kernel/fork.c"
    }
  ]
}