)]}'
{
  "log": [
    {
      "commit": "92476d7fc0326a409ab1d3864a04093a6be9aca7",
      "tree": "ea50a5a31522492d9915e0763a7adc6ac87c4fbc",
      "parents": [
        "8c7904a00b06d2ee51149794b619e07369fcf9d4"
      ],
      "author": {
        "name": "Eric W. Biederman",
        "email": "ebiederm@xmission.com",
        "time": "Fri Mar 31 02:31:42 2006 -0800"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Fri Mar 31 12:19:00 2006 -0800"
      },
      "message": "[PATCH] pidhash: Refactor the pid hash table\n\nSimplifies the code, reduces the need for 4 pid hash tables, and makes the\ncode more capable.\n\nIn the discussions I had with Oleg it was felt that to a large extent the\ncleanup itself justified the work.  With struct pid being dynamically\nallocated meant we could create the hash table entry when the pid was\nallocated and free the hash table entry when the pid was freed.  Instead of\nplaying with the hash lists when ever a process would attach or detach to a\nprocess.\n\nFor myself the fact that it gave what my previous task_ref patch gave for free\nwith simpler code was a big win.  The problem is that if you hold a reference\nto struct task_struct you lock in 10K of low memory.  If you do that in a user\ncontrollable way like /proc does, with an unprivileged but hostile user space\napplication with typical resource limits of 1000 fds and 100 processes I can\ntrigger the OOM killer by consuming all of low memory with task structs, on a\nmachine wight 1GB of low memory.\n\nIf I instead hold a reference to struct pid which holds a pointer to my\ntask_struct, I don\u0027t suffer from that problem because struct pid is 2 orders\nof magnitude smaller.  In fact struct pid is small enough that most other\nkernel data structures dwarf it, so simply limiting the number of referring\ndata structures is enough to prevent exhaustion of low memory.\n\nThis splits the current struct pid into two structures, struct pid and struct\npid_link, and reduces our number of hash tables from PIDTYPE_MAX to just one.\nstruct pid_link is the per process linkage into the hash tables and lives in\nstruct task_struct.  struct pid is given an indepedent lifetime, and holds\npointers to each of the pid types.\n\nThe independent life of struct pid simplifies attach_pid, and detach_pid,\nbecause we are always manipulating the list of pids and not the hash table.\nIn addition in giving struct pid an indpendent life it makes the concept much\nmore powerful.\n\nKernel data structures can now embed a struct pid * instead of a pid_t and\nnot suffer from pid wrap around problems or from keeping unnecessarily\nlarge amounts of memory allocated.\n\nSigned-off-by: Eric W. Biederman \u003cebiederm@xmission.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "73b9ebfe126a4a886ee46cbab637374d7024668a",
      "tree": "d7ba00d4ce76b49c1569334956cd196b35977a04",
      "parents": [
        "c97d98931ac52ef110b62d9b75c6a6f2bfbc1898"
      ],
      "author": {
        "name": "Oleg Nesterov",
        "email": "oleg@tv-sign.ru",
        "time": "Tue Mar 28 16:11:07 2006 -0800"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Tue Mar 28 18:36:41 2006 -0800"
      },
      "message": "[PATCH] pidhash: don\u0027t count idle threads\n\nfork_idle() does unhash_process() just after copy_process().  Contrary,\nboot_cpu\u0027s idle thread explicitely registers itself for each pid_type with nr\n\u003d 0.\n\ncopy_process() already checks p-\u003epid !\u003d 0 before process_counts++, I think we\ncan just skip attach_pid() calls and job control inits for idle threads and\nkill unhash_process().  We don\u0027t need to cleanup -\u003eproc_dentry in fork_idle()\nbecause with this patch idle threads are never hashed in\nkernel/pid.c:pid_hash[].\n\nWe don\u0027t need to hash pid \u003d\u003d 0 in pidmap_init().  free_pidmap() is never\ncalled with pid \u003d\u003d 0 arg, so it will never be reused.  So it is still possible\nto use pid \u003d\u003d 0 in any PIDTYPE_xxx namespace from kernel/pid.c\u0027s POV.\n\nHowever with this patch we don\u0027t hash pid \u003d\u003d 0 for PIDTYPE_PID case.  We still\nhave have PIDTYPE_PGID/PIDTYPE_SID entries with pid \u003d\u003d 0: /sbin/init and\nkernel threads which don\u0027t call daemonize().\n\nSigned-off-by: Oleg Nesterov \u003coleg@tv-sign.ru\u003e\nCc: \"Eric W. Biederman\" \u003cebiederm@xmission.com\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "d73d65293e3e2de7e916a89c8da30be0948afab7",
      "tree": "62b0ca76e3099c927f2960856dd060b136a8ccef",
      "parents": [
        "652486fb84a07ed750f1c11639518f55808bf555"
      ],
      "author": {
        "name": "Eric W. Biederman",
        "email": "ebiederm@xmission.com",
        "time": "Tue Mar 28 16:11:03 2006 -0800"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Tue Mar 28 18:36:40 2006 -0800"
      },
      "message": "[PATCH] pidhash: kill switch_exec_pids\n\nswitch_exec_pids is only called from de_thread by way of exec, and it is\nonly called when we are exec\u0027ing from a non thread group leader.\n\nCurrently switch_exec_pids gives the leader the pid of the thread and\nunhashes and rehashes all of the process groups.  The leader is already in\nthe EXIT_DEAD state so no one cares about it\u0027s pids.  The only concern for\nthe leader is that __unhash_process called from release_task will function\ncorrectly.  If we don\u0027t touch the leader at all we know that\n__unhash_process will work fine so there is no need to touch the leader.\n\nFor the task becomming the thread group leader, we just need to give it the\npid of the old thread group leader, add it to the task list, and attach it\nto the session and the process group of the thread group.\n\nCurrently de_thread is also adding the task to the task list which is just\nsilly.\n\nCurrently the only leader of __detach_pid besides detach_pid is\nswitch_exec_pids because of the ugly extra work that was being\nperformed.\n\nSo this patch removes switch_exec_pids because it is doing too much, it is\ncreating an unnecessary special case in pid.c, duing work duplicated in\nde_thread, and generally obscuring what it is going on.\n\nThe necessary work is added to de_thread, and it seems to be a little\nclearer there what is going on.\n\nSigned-off-by: Eric W. Biederman \u003cebiederm@xmission.com\u003e\nCc: Oleg Nesterov \u003coleg@tv-sign.ru\u003e\nCc: Kirill Korotaev \u003cdev@sw.ru\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "e56d090310d7625ecb43a1eeebd479f04affb48b",
      "tree": "2f479215dff4a2d8f3a9ed85200a5bc4f51534be",
      "parents": [
        "4369ef3c3e9d3bd9b879580678778f558d481e90"
      ],
      "author": {
        "name": "Ingo Molnar",
        "email": "mingo@elte.hu",
        "time": "Sun Jan 08 01:01:37 2006 -0800"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@g5.osdl.org",
        "time": "Sun Jan 08 20:13:40 2006 -0800"
      },
      "message": "[PATCH] RCU signal handling\n\nRCU tasklist_lock and RCU signal handling: send signals RCU-read-locked\ninstead of tasklist_lock read-locked.  This is a scalability improvement on\nSMP and a preemption-latency improvement under PREEMPT_RCU.\n\nSigned-off-by: Paul E. McKenney \u003cpaulmck@us.ibm.com\u003e\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\nAcked-by: William Irwin \u003cwli@holomorphy.com\u003e\nCc: Roland McGrath \u003croland@redhat.com\u003e\nCc: Oleg Nesterov \u003coleg@tv-sign.ru\u003e\nSigned-off-by: Andrew Morton \u003cakpm@osdl.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@osdl.org\u003e\n"
    },
    {
      "commit": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
      "tree": "0bba044c4ce775e45a88a51686b5d9f90697ea9d",
      "parents": [],
      "author": {
        "name": "Linus Torvalds",
        "email": "torvalds@ppc970.osdl.org",
        "time": "Sat Apr 16 15:20:36 2005 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@ppc970.osdl.org",
        "time": "Sat Apr 16 15:20:36 2005 -0700"
      },
      "message": "Linux-2.6.12-rc2\n\nInitial git repository build. I\u0027m not bothering with the full history,\neven though we have it. We can create a separate \"historical\" git\narchive of that later if we want to, and in the meantime it\u0027s about\n3.2GB when imported into git - space that would just make the early\ngit days unnecessarily complicated, when we don\u0027t have a lot of good\ninfrastructure for it.\n\nLet it rip!\n"
    }
  ]
}