)]}'
{
  "commit": "1663f26df3df7df3720306ca67f5ea8296d68fa1",
  "tree": "6ad80b7ccc7d093c0a14532affa376452f523afe",
  "parents": [
    "17cc4dfeda97636d67e83de8cd41940b65a93bc7"
  ],
  "author": {
    "name": "Tejun Heo",
    "email": "tj@kernel.org",
    "time": "Wed Feb 22 15:41:39 2017 -0800"
  },
  "committer": {
    "name": "Linus Torvalds",
    "email": "torvalds@linux-foundation.org",
    "time": "Wed Feb 22 16:41:27 2017 -0800"
  },
  "message": "slub: make sysfs directories for memcg sub-caches optional\n\nSLUB creates a per-cache directory under /sys/kernel/slab which hosts a\nbunch of debug files.  Usually, there aren\u0027t that many caches on a\nsystem and this doesn\u0027t really matter; however, if memcg is in use, each\ncache can have per-cgroup sub-caches.  SLUB creates the same directories\nfor these sub-caches under /sys/kernel/slab/$CACHE/cgroup.\n\nUnfortunately, because there can be a lot of cgroups, active or\ndraining, the product of the numbers of caches, cgroups and files in\neach directory can reach a very high number - hundreds of thousands is\ncommonplace.  Millions and beyond aren\u0027t difficult to reach either.\n\nWhat\u0027s under /sys/kernel/slab is primarily for debugging and the\ninformation and control on the a root cache already cover its\nsub-caches.  While having a separate directory for each sub-cache can be\nhelpful for development, it doesn\u0027t make much sense to pay this amount\nof overhead by default.\n\nThis patch introduces a boot parameter slub_memcg_sysfs which determines\nwhether to create sysfs directories for per-memcg sub-caches.  It also\nadds CONFIG_SLUB_MEMCG_SYSFS_ON which determines the boot parameter\u0027s\ndefault value and defaults to 0.\n\n[akpm@linux-foundation.org: kset_unregister(NULL) is legal]\nLink: http://lkml.kernel.org/r/20170204145203.GB26958@mtj.duckdns.org\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\nCc: Christoph Lameter \u003ccl@linux.com\u003e\nCc: Pekka Enberg \u003cpenberg@kernel.org\u003e\nCc: David Rientjes \u003crientjes@google.com\u003e\nCc: Joonsoo Kim \u003ciamjoonsoo.kim@lge.com\u003e\nCc: Vladimir Davydov \u003cvdavydov.dev@gmail.com\u003e\nCc: Michal Hocko \u003cmhocko@kernel.org\u003e\nCc: Johannes Weiner \u003channes@cmpxchg.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": "d05533e6120ba8c8ea01e769cdc30aa4125dcbe6",
      "old_mode": 33188,
      "old_path": "Documentation/admin-guide/kernel-parameters.txt",
      "new_id": "986e44387dad493e268ab93253120df73abc3045",
      "new_mode": 33188,
      "new_path": "Documentation/admin-guide/kernel-parameters.txt"
    },
    {
      "type": "modify",
      "old_id": "55bb6fbc294eeca90b936cd50bf1da4b7e487fb1",
      "old_mode": 33188,
      "old_path": "init/Kconfig",
      "new_id": "22f437ff65e54697626f449e362f122e0e94ccea",
      "new_mode": 33188,
      "new_path": "init/Kconfig"
    },
    {
      "type": "modify",
      "old_id": "af38aaad34b0244760af75edfe0200222f5b6e48",
      "old_mode": 33188,
      "old_path": "mm/slub.c",
      "new_id": "7f4bc7027ed53536efaaf5663f007bd2442de503",
      "new_mode": 33188,
      "new_path": "mm/slub.c"
    }
  ]
}