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  1. 02 8月, 2009 6 次提交
    • M
      lockdep: Reintroduce generation count to make BFS faster · e351b660
      由 Ming Lei 提交于 
      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: NMing Lei <tom.leiming@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "David S. Miller" <davem@davemloft.net>
LKML-Reference: <1248274089-6358-1-git-send-email-tom.leiming@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      e351b660
    • P
      lockdep: Deal with many similar locks · bb97a91e
      由 Peter Zijlstra 提交于 
      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: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      bb97a91e
    • P
      lockdep: Introduce lockdep_assert_held() · f607c668
      由 Peter Zijlstra 提交于 
      Add a lockdep helper to validate that we indeed are the owner
of a lock.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      f607c668
    • P
      lockdep: Fix style nits · 98c33edd
      由 Peter Zijlstra 提交于 
      fixes a few comments and whitespaces that annoyed me.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      98c33edd
    • P
      lockdep: Fix backtraces · 4f84f433
      由 Peter Zijlstra 提交于 
      Truncate stupid -1 entries in backtraces.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1248096665.15751.8816.camel@twins>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      4f84f433
    • I
      lockdep: Fix BFS build · bbfa2622
      由 Ingo Molnar 提交于 
      Fix:

  kernel/built-in.o: In function `lockdep_stats_show':
  lockdep_proc.c:(.text+0x48202): undefined reference to `max_bfs_queue_depth'

As max_bfs_queue_depth is only available under
CONFIG_PROVE_LOCKING=y.

Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      bbfa2622
  3. 24 7月, 2009 10 次提交
  5. 23 7月, 2009 24 次提交