linux-toradex.git/include/linux/lockdep.h, branch v4.11-rc3

locking/lockdep: Provide a type check for lock_is_held

2016-11-30T03:32:25+00:00

Christoph requested lockdep_assert_held() variants that distinguish
between held-for-read or held-for-write.

Provide:

  int lock_is_held_type(struct lockdep_map *lock, int read)

which takes the same argument as lock_acquire(.read) and matches it to
the held_lock instance.

Use of this function should be gated by the debug_locks variable. When
that is 0 the return value of the lock_is_held_type() function is
undefined. This is done to allow both negative and positive tests for
holding locks.

By default we provide (positive) lockdep_assert_held{,_exclusive,_read}()
macros.

Requested-by: Christoph Hellwig 
Signed-off-by: Peter Zijlstra (Intel) 
Tested-by: Jens Axboe 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Dave Chinner

lockdep: make MAX_LOCKDEP_SUBCLASSES unconditionally visible

2016-09-24T08:48:32+00:00

This define is needed by i2c_adapter_depth() to detect if we don't
exceed the maximum number of lock subclasses. Make it visible even
if lockdep is disabled.

Signed-off-by: Bartosz Golaszewski 
Acked-by: Peter Rosin 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: Wolfram Sang

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

2016-05-16T21:47:16+00:00

Pull scheduler updates from Ingo Molnar:

 - massive CPU hotplug rework (Thomas Gleixner)

 - improve migration fairness (Peter Zijlstra)

 - CPU load calculation updates/cleanups (Yuyang Du)

 - cpufreq updates (Steve Muckle)

 - nohz optimizations (Frederic Weisbecker)

 - switch_mm() micro-optimization on x86 (Andy Lutomirski)

 - ... lots of other enhancements, fixes and cleanups.

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (66 commits)
  ARM: Hide finish_arch_post_lock_switch() from modules
  sched/core: Provide a tsk_nr_cpus_allowed() helper
  sched/core: Use tsk_cpus_allowed() instead of accessing ->cpus_allowed
  sched/loadavg: Fix loadavg artifacts on fully idle and on fully loaded systems
  sched/fair: Correct unit of load_above_capacity
  sched/fair: Clean up scale confusion
  sched/nohz: Fix affine unpinned timers mess
  sched/fair: Fix fairness issue on migration
  sched/core: Kill sched_class::task_waking to clean up the migration logic
  sched/fair: Prepare to fix fairness problems on migration
  sched/fair: Move record_wakee()
  sched/core: Fix comment typo in wake_q_add()
  sched/core: Remove unused variable
  sched: Make hrtick_notifier an explicit call
  sched/fair: Make ilb_notifier an explicit call
  sched/hotplug: Make activate() the last hotplug step
  sched/hotplug: Move migration CPU_DYING to sched_cpu_dying()
  sched/migration: Move CPU_ONLINE into scheduler state
  sched/migration: Move calc_load_migrate() into CPU_DYING
  sched/migration: Move prepare transition to SCHED_STARTING state
  ...

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

2016-05-16T20:41:02+00:00

Pull support for killable rwsems from Ingo Molnar:
 "This, by Michal Hocko, implements down_write_killable().

  The main usecase will be to update mm_sem usage sites to use this new
  API, to allow the mm-reaper introduced in commit aac453635549 ("mm,
  oom: introduce oom reaper") to tear down oom victim address spaces
  asynchronously with minimum latencies and without deadlock worries"

[ The vfs will want it too as the inode lock is changed from a mutex to
  a rwsem due to the parallel lookup and readdir updates ]

* 'locking-rwsem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Fix comment on register clobbering
  locking/rwsem: Fix down_write_killable()
  locking/rwsem, x86: Add frame annotation for call_rwsem_down_write_failed_killable()
  locking/rwsem: Provide down_write_killable()
  locking/rwsem, x86: Provide __down_write_killable()
  locking/rwsem, s390: Provide __down_write_killable()
  locking/rwsem, ia64: Provide __down_write_killable()
  locking/rwsem, alpha: Provide __down_write_killable()
  locking/rwsem: Introduce basis for down_write_killable()
  locking/rwsem, sparc: Drop superfluous arch specific implementation
  locking/rwsem, sh: Drop superfluous arch specific implementation
  locking/rwsem, xtensa: Drop superfluous arch specific implementation
  locking/rwsem: Drop explicit memory barriers
  locking/rwsem: Get rid of __down_write_nested()

Merge branch 'sched/urgent' into sched/core to pick up fixes

2016-05-12T07:18:13+00:00

Signed-off-by: Ingo Molnar

locking/lockdep, sched/core: Implement a better lock pinning scheme

2016-05-05T07:23:59+00:00

The problem with the existing lock pinning is that each pin is of
value 1; this mean you can simply unpin if you know its pinned,
without having any extra information.

This scheme generates a random (16 bit) cookie for each pin and
requires this same cookie to unpin. This means you have to keep the
cookie in context.

No objsize difference for !LOCKDEP kernels.

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

lockdep: Fix lock_chain::base size

2016-04-23T11:53:03+00:00

lock_chain::base is used to store an index into the chain_hlocks[]
array, however that array contains more elements than can be indexed
using the u16.

Change the lock_chain structure to use a bitfield to encode the data
it needs and add BUILD_BUG_ON() assertions to check the fields are
wide enough.

Also, for DEBUG_LOCKDEP, assert that we don't run out of elements of
that array; as that would wreck the collision detectoring.

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Alfredo Alvarez Fernandez 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Sedat Dilek 
Cc: Theodore Ts'o 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20160330093659.GS3408@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar

locking/rwsem: Provide down_write_killable()

2016-04-22T06:58:33+00:00

Now that all the architectures implement the necessary glue code
we can introduce down_write_killable(). The only difference wrt. regular
down_write() is that the slow path waits in TASK_KILLABLE state and the
interruption by the fatal signal is reported as -EINTR to the caller.

Signed-off-by: Michal Hocko 
Cc: Andrew Morton 
Cc: Chris Zankel 
Cc: David S. Miller 
Cc: Linus Torvalds 
Cc: Max Filippov 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Signed-off-by: Davidlohr Bueso 
Cc: Signed-off-by: Jason Low 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/1460041951-22347-12-git-send-email-mhocko@kernel.org
Signed-off-by: Ingo Molnar

locking/lockdep: Eliminate lockdep_init()

2016-02-09T11:03:25+00:00

Lockdep is initialized at compile time now.  Get rid of lockdep_init().

Signed-off-by: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Cc: Linus Torvalds 
Cc: Mike Krinkin 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Cc: mm-commits@vger.kernel.org
Signed-off-by: Ingo Molnar

locking/lockdep: Convert hash tables to hlists

2016-02-09T11:03:25+00:00

Mike said:

: CONFIG_UBSAN_ALIGNMENT breaks x86-64 kernel with lockdep enabled, i.e.
: kernel with CONFIG_UBSAN_ALIGNMENT=y fails to load without even any error
: message.
:
: The problem is that ubsan callbacks use spinlocks and might be called
: before lockdep is initialized.  Particularly this line in the
: reserve_ebda_region function causes problem:
:
: lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);
:
: If i put lockdep_init() before reserve_ebda_region call in
: x86_64_start_reservations kernel loads well.

Fix this ordering issue permanently: change lockdep so that it uses hlists
for the hash tables.  Unlike a list_head, an hlist_head is in its
initialized state when it is all-zeroes, so lockdep is ready for operation
immediately upon boot - lockdep_init() need not have run.

The patch will also save some memory.

Probably lockdep_init() and lockdep_initialized can be done away with now.

Suggested-by: Mike Krinkin 
Reported-by: Mike Krinkin 
Signed-off-by: Andrew Morton 
Cc: Andrey Ryabinin 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Cc: mm-commits@vger.kernel.org
Signed-off-by: Ingo Molnar