Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core locking changes from Ingo Molnar:
 "The biggest changes:

   - add lockdep support for seqcount/seqlocks structures, this
     unearthed both bugs and required extra annotation.

   - move the various kernel locking primitives to the new
     kernel/locking/ directory"

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  block: Use u64_stats_init() to initialize seqcounts
  locking/lockdep: Mark __lockdep_count_forward_deps() as static
  lockdep/proc: Fix lock-time avg computation
  locking/doc: Update references to kernel/mutex.c
  ipv6: Fix possible ipv6 seqlock deadlock
  cpuset: Fix potential deadlock w/ set_mems_allowed
  seqcount: Add lockdep functionality to seqcount/seqlock structures
  net: Explicitly initialize u64_stats_sync structures for lockdep
  locking: Move the percpu-rwsem code to kernel/locking/
  locking: Move the lglocks code to kernel/locking/
  locking: Move the rwsem code to kernel/locking/
  locking: Move the rtmutex code to kernel/locking/
  locking: Move the semaphore core to kernel/locking/
  locking: Move the spinlock code to kernel/locking/
  locking: Move the lockdep code to kernel/locking/
  locking: Move the mutex code to kernel/locking/
  hung_task debugging: Add tracepoint to report the hang
  x86/locking/kconfig: Update paravirt spinlock Kconfig description
  lockstat: Report avg wait and hold times
  lockdep, x86/alternatives: Drop ancient lockdep fixup message
  ...

3 files changed, 67 insertions, 68 deletions

diff --git a/Documentation/DocBook/kernel-locking.tmpl b/Documentation/DocBook/kernel-locking.tmpl
index 09e884e5b9f..19f2a5a5a5b 100644
--- a/Documentation/DocBook/kernel-locking.tmpl
+++ b/Documentation/DocBook/kernel-locking.tmpl
@@ -1958,7 +1958,7 @@ machines due to caching.
   <chapter id="apiref-mutex">
    <title>Mutex API reference</title>
 !Iinclude/linux/mutex.h
-!Ekernel/mutex.c
+!Ekernel/locking/mutex.c
   </chapter>
 
   <chapter id="apiref-futex">
diff --git a/Documentation/lockstat.txt b/Documentation/lockstat.txt
index dd2f7b26ca3..72d01068975 100644
--- a/Documentation/lockstat.txt
+++ b/Documentation/lockstat.txt
@@ -46,16 +46,14 @@ With these hooks we provide the following statistics:
  contentions       - number of lock acquisitions that had to wait
  wait time min     - shortest (non-0) time we ever had to wait for a lock
            max     - longest time we ever had to wait for a lock
-           total   - total time we spend waiting on this lock
+	   total   - total time we spend waiting on this lock
+	   avg     - average time spent waiting on this lock
  acq-bounces       - number of lock acquisitions that involved x-cpu data
  acquisitions      - number of times we took the lock
  hold time min     - shortest (non-0) time we ever held the lock
-           max     - longest time we ever held the lock
-           total   - total time this lock was held
-
-From these number various other statistics can be derived, such as:
-
- hold time average = hold time total / acquisitions
+	   max     - longest time we ever held the lock
+	   total   - total time this lock was held
+	   avg     - average time this lock was held
 
 These numbers are gathered per lock class, per read/write state (when
 applicable).
@@ -84,37 +82,38 @@ Look at the current lock statistics:
 
 # less /proc/lock_stat
 
-01 lock_stat version 0.3
-02 -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-03                               class name    con-bounces    contentions   waittime-min   waittime-max waittime-total    acq-bounces   acquisitions   holdtime-min   holdtime-max holdtime-total
-04 -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+01 lock_stat version 0.4
+02-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+03                              class name    con-bounces    contentions   waittime-min   waittime-max waittime-total   waittime-avg    acq-bounces   acquisitions   holdtime-min   holdtime-max holdtime-total   holdtime-avg
+04-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 05
-06                          &mm->mmap_sem-W:           233            538 18446744073708       22924.27      607243.51           1342          45806           1.71        8595.89     1180582.34
-07                          &mm->mmap_sem-R:           205            587 18446744073708       28403.36      731975.00           1940         412426           0.58      187825.45     6307502.88
-08                          ---------------
-09                            &mm->mmap_sem            487          [<ffffffff8053491f>] do_page_fault+0x466/0x928
-10                            &mm->mmap_sem            179          [<ffffffff802a6200>] sys_mprotect+0xcd/0x21d
-11                            &mm->mmap_sem            279          [<ffffffff80210a57>] sys_mmap+0x75/0xce
-12                            &mm->mmap_sem             76          [<ffffffff802a490b>] sys_munmap+0x32/0x59
-13                          ---------------
-14                            &mm->mmap_sem            270          [<ffffffff80210a57>] sys_mmap+0x75/0xce
-15                            &mm->mmap_sem            431          [<ffffffff8053491f>] do_page_fault+0x466/0x928
-16                            &mm->mmap_sem            138          [<ffffffff802a490b>] sys_munmap+0x32/0x59
-17                            &mm->mmap_sem            145          [<ffffffff802a6200>] sys_mprotect+0xcd/0x21d
+06                         &mm->mmap_sem-W:            46             84           0.26         939.10       16371.53         194.90          47291        2922365           0.16     2220301.69 17464026916.32        5975.99
+07                         &mm->mmap_sem-R:            37            100           1.31      299502.61      325629.52        3256.30         212344       34316685           0.10        7744.91    95016910.20           2.77
+08                         ---------------
+09                           &mm->mmap_sem              1          [<ffffffff811502a7>] khugepaged_scan_mm_slot+0x57/0x280
+19                           &mm->mmap_sem             96          [<ffffffff815351c4>] __do_page_fault+0x1d4/0x510
+11                           &mm->mmap_sem             34          [<ffffffff81113d77>] vm_mmap_pgoff+0x87/0xd0
+12                           &mm->mmap_sem             17          [<ffffffff81127e71>] vm_munmap+0x41/0x80
+13                         ---------------
+14                           &mm->mmap_sem              1          [<ffffffff81046fda>] dup_mmap+0x2a/0x3f0
+15                           &mm->mmap_sem             60          [<ffffffff81129e29>] SyS_mprotect+0xe9/0x250
+16                           &mm->mmap_sem             41          [<ffffffff815351c4>] __do_page_fault+0x1d4/0x510
+17                           &mm->mmap_sem             68          [<ffffffff81113d77>] vm_mmap_pgoff+0x87/0xd0
 18
-19 ...............................................................................................................................................................................................
+19.............................................................................................................................................................................................................................
 20
-21                              dcache_lock:           621            623           0.52         118.26        1053.02           6745          91930           0.29         316.29      118423.41
-22                              -----------
-23                              dcache_lock            179          [<ffffffff80378274>] _atomic_dec_and_lock+0x34/0x54
-24                              dcache_lock            113          [<ffffffff802cc17b>] d_alloc+0x19a/0x1eb
-25                              dcache_lock             99          [<ffffffff802ca0dc>] d_rehash+0x1b/0x44
-26                              dcache_lock            104          [<ffffffff802cbca0>] d_instantiate+0x36/0x8a
-27                              -----------
-28                              dcache_lock            192          [<ffffffff80378274>] _atomic_dec_and_lock+0x34/0x54
-29                              dcache_lock             98          [<ffffffff802ca0dc>] d_rehash+0x1b/0x44
-30                              dcache_lock             72          [<ffffffff802cc17b>] d_alloc+0x19a/0x1eb
-31                              dcache_lock            112          [<ffffffff802cbca0>] d_instantiate+0x36/0x8a
+21                         unix_table_lock:           110            112           0.21          49.24         163.91           1.46          21094          66312           0.12         624.42       31589.81           0.48
+22                         ---------------
+23                         unix_table_lock             45          [<ffffffff8150ad8e>] unix_create1+0x16e/0x1b0
+24                         unix_table_lock             47          [<ffffffff8150b111>] unix_release_sock+0x31/0x250
+25                         unix_table_lock             15          [<ffffffff8150ca37>] unix_find_other+0x117/0x230
+26                         unix_table_lock              5          [<ffffffff8150a09f>] unix_autobind+0x11f/0x1b0
+27                         ---------------
+28                         unix_table_lock             39          [<ffffffff8150b111>] unix_release_sock+0x31/0x250
+29                         unix_table_lock             49          [<ffffffff8150ad8e>] unix_create1+0x16e/0x1b0
+30                         unix_table_lock             20          [<ffffffff8150ca37>] unix_find_other+0x117/0x230
+31                         unix_table_lock              4          [<ffffffff8150a09f>] unix_autobind+0x11f/0x1b0
+
 
 This excerpt shows the first two lock class statistics. Line 01 shows the
 output version - each time the format changes this will be updated. Line 02-04
@@ -131,30 +130,30 @@ The integer part of the time values is in us.
 
 Dealing with nested locks, subclasses may appear:
 
-32...............................................................................................................................................................................................
+32...........................................................................................................................................................................................................................
 33
-34                               &rq->lock:         13128          13128           0.43         190.53      103881.26          97454        3453404           0.00         401.11    13224683.11
+34                               &rq->lock:       13128          13128           0.43         190.53      103881.26           7.91          97454        3453404           0.00         401.11    13224683.11           3.82
 35                               ---------
-36                               &rq->lock            645          [<ffffffff8103bfc4>] task_rq_lock+0x43/0x75
-37                               &rq->lock            297          [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
-38                               &rq->lock            360          [<ffffffff8103c4c5>] select_task_rq_fair+0x1f0/0x74a
-39                               &rq->lock            428          [<ffffffff81045f98>] scheduler_tick+0x46/0x1fb
+36                               &rq->lock          645          [<ffffffff8103bfc4>] task_rq_lock+0x43/0x75
+37                               &rq->lock          297          [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
+38                               &rq->lock          360          [<ffffffff8103c4c5>] select_task_rq_fair+0x1f0/0x74a
+39                               &rq->lock          428          [<ffffffff81045f98>] scheduler_tick+0x46/0x1fb
 40                               ---------
-41                               &rq->lock             77          [<ffffffff8103bfc4>] task_rq_lock+0x43/0x75
-42                               &rq->lock            174          [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
-43                               &rq->lock           4715          [<ffffffff8103ed4b>] double_rq_lock+0x42/0x54
-44                               &rq->lock            893          [<ffffffff81340524>] schedule+0x157/0x7b8
+41                               &rq->lock           77          [<ffffffff8103bfc4>] task_rq_lock+0x43/0x75
+42                               &rq->lock          174          [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
+43                               &rq->lock         4715          [<ffffffff8103ed4b>] double_rq_lock+0x42/0x54
+44                               &rq->lock          893          [<ffffffff81340524>] schedule+0x157/0x7b8
 45
-46...............................................................................................................................................................................................
+46...........................................................................................................................................................................................................................
 47
-48                             &rq->lock/1:         11526          11488           0.33         388.73      136294.31          21461          38404           0.00          37.93      109388.53
+48                             &rq->lock/1:        1526          11488           0.33         388.73      136294.31          11.86          21461          38404           0.00          37.93      109388.53           2.84
 49                             -----------
-50                             &rq->lock/1          11526          [<ffffffff8103ed58>] double_rq_lock+0x4f/0x54
+50                             &rq->lock/1        11526          [<ffffffff8103ed58>] double_rq_lock+0x4f/0x54
 51                             -----------
-52                             &rq->lock/1           5645          [<ffffffff8103ed4b>] double_rq_lock+0x42/0x54
-53                             &rq->lock/1           1224          [<ffffffff81340524>] schedule+0x157/0x7b8
-54                             &rq->lock/1           4336          [<ffffffff8103ed58>] double_rq_lock+0x4f/0x54
-55                             &rq->lock/1            181          [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
+52                             &rq->lock/1         5645          [<ffffffff8103ed4b>] double_rq_lock+0x42/0x54
+53                             &rq->lock/1         1224          [<ffffffff81340524>] schedule+0x157/0x7b8
+54                             &rq->lock/1         4336          [<ffffffff8103ed58>] double_rq_lock+0x4f/0x54
+55                             &rq->lock/1          181          [<ffffffff8104ba65>] try_to_wake_up+0x127/0x25a
 
 Line 48 shows statistics for the second subclass (/1) of &rq->lock class
 (subclass starts from 0), since in this case, as line 50 suggests,
@@ -163,16 +162,16 @@ double_rq_lock actually acquires a nested lock of two spinlocks.
 View the top contending locks:
 
 # grep : /proc/lock_stat | head
-              &inode->i_data.tree_lock-W:            15          21657           0.18     1093295.30 11547131054.85             58          10415           0.16          87.51        6387.60
-              &inode->i_data.tree_lock-R:             0              0           0.00           0.00           0.00          23302         231198           0.25           8.45       98023.38
-                             dcache_lock:          1037           1161           0.38          45.32         774.51           6611         243371           0.15         306.48       77387.24
-                         &inode->i_mutex:           161            286 18446744073709       62882.54     1244614.55           3653          20598 18446744073709       62318.60     1693822.74
-                         &zone->lru_lock:            94             94           0.53           7.33          92.10           4366          32690           0.29          59.81       16350.06
-              &inode->i_data.i_mmap_mutex:            79             79           0.40           3.77          53.03          11779          87755           0.28         116.93       29898.44
-                        &q->__queue_lock:            48             50           0.52          31.62          86.31            774          13131           0.17         113.08       12277.52
-                        &rq->rq_lock_key:            43             47           0.74          68.50         170.63           3706          33929           0.22         107.99       17460.62
-                      &rq->rq_lock_key#2:            39             46           0.75           6.68          49.03           2979          32292           0.17         125.17       17137.63
-                         tasklist_lock-W:            15             15           1.45          10.87          32.70           1201           7390           0.58          62.55       13648.47
+			clockevents_lock:       2926159        2947636           0.15       46882.81  1784540466.34         605.41        3381345        3879161           0.00        2260.97    53178395.68          13.71
+		     tick_broadcast_lock:        346460         346717           0.18        2257.43    39364622.71         113.54        3642919        4242696           0.00        2263.79    49173646.60          11.59
+		  &mapping->i_mmap_mutex:        203896         203899           3.36      645530.05 31767507988.39      155800.21        3361776        8893984           0.17        2254.15    14110121.02           1.59
+			       &rq->lock:        135014         136909           0.18         606.09      842160.68           6.15        1540728       10436146           0.00         728.72    17606683.41           1.69
+	       &(&zone->lru_lock)->rlock:         93000          94934           0.16          59.18      188253.78           1.98        1199912        3809894           0.15         391.40     3559518.81           0.93
+			 tasklist_lock-W:         40667          41130           0.23        1189.42      428980.51          10.43         270278         510106           0.16         653.51     3939674.91           7.72
+			 tasklist_lock-R:         21298          21305           0.20        1310.05      215511.12          10.12         186204         241258           0.14        1162.33     1179779.23           4.89
+			      rcu_node_1:         47656          49022           0.16         635.41      193616.41           3.95         844888        1865423           0.00         764.26     1656226.96           0.89
+       &(&dentry->d_lockref.lock)->rlock:         39791          40179           0.15        1302.08       88851.96           2.21        2790851       12527025           0.10        1910.75     3379714.27           0.27
+			      rcu_node_0:         29203          30064           0.16         786.55     1555573.00          51.74          88963         244254           0.00         398.87      428872.51           1.76
 
 Clear the statistics:
 
diff --git a/Documentation/mutex-design.txt b/Documentation/mutex-design.txt
index 38c10fd7f41..1dfe62c3641 100644
--- a/Documentation/mutex-design.txt
+++ b/Documentation/mutex-design.txt
@@ -116,11 +116,11 @@ using mutexes at the moment, please let me know if you find any. ]
 Implementation of mutexes
 -------------------------
 
-'struct mutex' is the new mutex type, defined in include/linux/mutex.h
-and implemented in kernel/mutex.c. It is a counter-based mutex with a
-spinlock and a wait-list. The counter has 3 states: 1 for "unlocked",
-0 for "locked" and negative numbers (usually -1) for "locked, potential
-waiters queued".
+'struct mutex' is the new mutex type, defined in include/linux/mutex.h and
+implemented in kernel/locking/mutex.c. It is a counter-based mutex with a
+spinlock and a wait-list. The counter has 3 states: 1 for "unlocked", 0 for
+"locked" and negative numbers (usually -1) for "locked, potential waiters
+queued".
 
 the APIs of 'struct mutex' have been streamlined: