linux-toradex.git/kernel/lockdep.c, branch tegra-10.9.7

lockdep: Use cpu_clock() for lockstat

2009-10-09T13:56:44+00:00

Some tracepoint magic (TRACE_EVENT(lock_acquired)) relies on
the fact that lock hold times are positive and uses div64 on
that. That triggered a build warning on MIPS, and probably
causes bad output in certain circumstances as well.

Make it truly positive.

Reported-by: Andrew Morton 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1254818502.21044.112.camel@laptop>
Signed-off-by: Ingo Molnar

lockdep: use new arch_is_kernel_data()

2009-09-23T14:39:30+00:00

This allows lockdep to locate symbols that are in arch-specific data
sections (such as data in Blackfin on-chip SRAM regions).

Signed-off-by: Mike Frysinger 
Cc: Ingo Molnar 
Cc: Robin Getz 
Cc: Sam Ravnborg 
Cc: Peter Zijlstra 
Cc: Arnd Bergmann 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lockdep: Remove recursion stattistics

2009-08-29T11:22:36+00:00

Since lockdep has introduced BFS to avoid recursion, statistics
for recursion does not make any sense now. So remove them.

Signed-off-by: Ming Lei 
Cc: a.p.zijlstra@chello.nl
LKML-Reference: <1251542879-5211-1-git-send-email-tom.leiming@gmail.com>
Signed-off-by: Ingo Molnar

lockdep: Fix memory usage info of BFS

2009-08-02T13:45:28+00:00

The unit is KB, so sizeof(struct circular_queue) should be
divided by 1024.

Signed-off-by: Ming Lei 
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Cc: davem@davemloft.net
Cc: Ming Lei 
Cc: a.p.zijlstra@chello.nl
LKML-Reference: <1249220616-7190-1-git-send-email-tom.leiming@gmail.com>
Signed-off-by: Ingo Molnar

lockdep: Reintroduce generation count to make BFS faster

2009-08-02T13:41:37+00:00

We still can apply DaveM's generation count optimization to
BFS, based on the following idea:

 - before doing each BFS, increase the global generation id
   by 1

 - if one node in the graph has been visited, mark it as
   visited by storing the current global generation id into
   the node's dep_gen_id field

 - so we can decide if one node has been visited already, by
   comparing the node's dep_gen_id with the global generation id.

By applying DaveM's generation count optimization to current
implementation of BFS, we gain the following advantages:

 - we save MAX_LOCKDEP_ENTRIES/8 bytes memory;

 - we remove the bitmap_zero(bfs_accessed, MAX_LOCKDEP_ENTRIES);
   in each BFS, which is very time-consuming since
   MAX_LOCKDEP_ENTRIES may be very large.(16384UL)

Signed-off-by: Ming Lei 
Signed-off-by: Peter Zijlstra 
Cc: "David S. Miller" 
LKML-Reference: <1248274089-6358-1-git-send-email-tom.leiming@gmail.com>
Signed-off-by: Ingo Molnar

lockdep: Deal with many similar locks

2009-08-02T13:41:35+00:00

spin_lock_nest_lock() allows to take many instances of the same
class, this can easily lead to overflow of MAX_LOCK_DEPTH.

To avoid this overflow, we'll stop accounting instances but
start reference counting the class in the held_lock structure.

[ We could maintain a list of instances, if we'd move the hlock
  stuff into __lock_acquired(), but that would require
  significant modifications to the current code. ]

We restrict this mode to spin_lock_nest_lock() only, because it
degrades the lockdep quality due to lost of instance.

For lockstat this means we don't track lock statistics for any
but the first lock in the series.

Currently nesting is limited to 11 bits because that was the
spare space available in held_lock. This yields a 2048
instances maximium.

Signed-off-by: Peter Zijlstra 
Cc: Marcelo Tosatti 
Cc: Linus Torvalds 
Signed-off-by: Ingo Molnar

lockdep: Introduce lockdep_assert_held()

2009-08-02T13:41:34+00:00

Add a lockdep helper to validate that we indeed are the owner
of a lock.

Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

lockdep: Fix style nits

2009-08-02T13:41:32+00:00

fixes a few comments and whitespaces that annoyed me.

Signed-off-by: Peter Zijlstra 
Signed-off-by: Ingo Molnar

lockdep: Fix backtraces

2009-08-02T13:41:31+00:00

Truncate stupid -1 entries in backtraces.

Signed-off-by: Peter Zijlstra 
LKML-Reference: <1248096665.15751.8816.camel@twins>
Signed-off-by: Ingo Molnar

lockdep: BFS cleanup

2009-07-24T08:53:29+00:00

Some cleanups of the lockdep code after the BFS series:

 - Remove the last traces of the generation id
 - Fixup comment style
 - Move the bfs routines into lockdep.c
 - Cleanup the bfs routines

[ tom.leiming@gmail.com: Fix crash ]
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1246201486-7308-11-git-send-email-tom.leiming@gmail.com>
Signed-off-by: Ingo Molnar