Eric Lee / smarc-fsl-linux-kernel

26 Aug, 2008

1 commit

  • 2189459d2   lockstat: fix numerical output rounding error ... Browse Code »

    Fix rounding error in /proc/lock_stat numerical output.

    On occasion the two digit fractional part contains the three
    digit value '100'. This is due to a bug in the rounding algorithm
    which pushes values in the range '95..99' to '100' rather than
    to '00' + an increment to the integer part. For example,

    - 123456.100 old display
    + 123457.00 new display

    Signed-off-by: Ingo Molnar

    Joe Korty
     

16 Aug, 2008

1 commit

11 Aug, 2008

1 commit

01 Aug, 2008

1 commit

  • 419ca3f13   lockdep: fix combinatorial explosion in lock subgraph traversal ... Browse Code »

    When we traverse the graph, either forwards or backwards, we
    are interested in whether a certain property exists somewhere
    in a node reachable in the graph.

    Therefore it is never necessary to traverse through a node more
    than once to get a correct answer to the given query.

    Take advantage of this property using a global ID counter so that we
    need not clear all the markers in all the lock_class entries before
    doing a traversal. A new ID is choosen when we start to traverse, and
    we continue through a lock_class only if it's ID hasn't been marked
    with the new value yet.

    This short-circuiting is essential especially for high CPU count
    systems. The scheduler has a runqueue per cpu, and needs to take
    two runqueue locks at a time, which leads to long chains of
    backwards and forwards subgraphs from these runqueue lock nodes.
    Without the short-circuit implemented here, a graph traversal on
    a runqueue lock can take up to (1 << (N - 1)) checks on a system
    with N cpus.

    For anything more than 16 cpus or so, lockdep will eventually bring
    the machine to a complete standstill.

    Signed-off-by: David S. Miller
    Acked-by: Peter Zijlstra
    Signed-off-by: Ingo Molnar

    David Miller
     

24 Jun, 2008

1 commit

20 Jun, 2008

1 commit

13 Jun, 2008

1 commit

29 Apr, 2008

1 commit

12 Oct, 2007

1 commit

  • 94c61c0ae   lockdep: Avoid /proc/lockdep & lock_stat infinite output ... Browse Code »

    Both /proc/lockdep and /proc/lock_stat output may loop infinitely.

    When a read() requests an amount of data smaller than the amount of data
    that the seq_file's foo_show() outputs, the output starts looping and
    outputs the "stuck" element's data infinitely. There may be multiple
    sequential calls to foo_start(), foo_next()/foo_show(), and foo_stop()
    for a single open with sequential read of the file. The _start() does not
    have to start with the 0th element and _show() might be called multiple
    times in a row for the same element for a given open/read of the seq_file.

    Also header output should not be happening in _start(). All output should
    be in _show(), which SEQ_START_TOKEN is meant to help. Having output in
    _start() may also negatively impact seq_file's seq_read() and traverse()
    accounting.

    Signed-off-by: Tim Pepper
    Signed-off-by: Peter Zijlstra
    Signed-off-by: Ingo Molnar
    Cc: Ingo Molnar
    Cc: Al Viro

    Tim Pepper
     

01 Aug, 2007

1 commit

20 Jul, 2007

5 commits

  • d38e1d5aa   lockstat: better class name representation ... Browse Code »

    optionally add class->name_version and class->subclass to the class name

    Signed-off-by: Peter Zijlstra
    Cc: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     
  • 96645678c   lockstat: measure lock bouncing ... Browse Code »

    __acquire
    |
    lock _____
    | \
    | __contended
    | |
    | wait
    | _______/
    |/
    |
    __acquired
    |
    __release
    |
    unlock

    We measure acquisition and contention bouncing.

    This is done by recording a cpu stamp in each lock instance.

    Contention bouncing requires the cpu stamp to be set on acquisition. Hence we
    move __acquired into the generic path.

    __acquired is then used to measure acquisition bouncing by comparing the
    current cpu with the old stamp before replacing it.

    __contended is used to measure contention bouncing (only useful for preemptable
    locks)

    [akpm@linux-foundation.org: cleanups]
    Signed-off-by: Peter Zijlstra
    Acked-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     
  • 4b32d0a4e   lockdep: various fixes ... Browse Code »

    - update the copyright notices
    - use the default hash function
    - fix a thinko in a BUILD_BUG_ON
    - add a WARN_ON to spot inconsitent naming
    - fix a termination issue in /proc/lock_stat

    [akpm@linux-foundation.org: cleanups]
    Signed-off-by: Peter Zijlstra
    Acked-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     
  • c46261de0   lockstat: human readability tweaks ... Browse Code »

    Present all this fancy new lock statistics information:

    *warning, _wide_ output ahead*

    (output edited for purpose of brevity)

    # cat /proc/lock_stat
    lock_stat version 0.1
    -----------------------------------------------------------------------------------------------------------------------------------------------------------------
    class name contentions waittime-min waittime-max waittime-total acquisitions holdtime-min holdtime-max holdtime-total
    -----------------------------------------------------------------------------------------------------------------------------------------------------------------

    &inode->i_mutex: 14458 6.57 398832.75 2469412.23 6768876 0.34 11398383.65 339410830.89
    ---------------
    &inode->i_mutex 4486 [] pipe_wait+0x86/0x8d
    &inode->i_mutex 0 [] pipe_write_fasync+0x29/0x5d
    &inode->i_mutex 0 [] pipe_read+0x74/0x3a5
    &inode->i_mutex 0 [] do_lookup+0x81/0x1ae

    .................................................................................................................................................................

    &inode->i_data.tree_lock-W: 491 0.27 62.47 493.89 2477833 0.39 468.89 1146584.25
    &inode->i_data.tree_lock-R: 65 0.44 4.27 48.78 26288792 0.36 184.62 10197458.24
    --------------------------
    &inode->i_data.tree_lock 46 [] __do_page_cache_readahead+0x69/0x24f
    &inode->i_data.tree_lock 31 [] add_to_page_cache+0x31/0xba
    &inode->i_data.tree_lock 0 [] __do_page_cache_readahead+0xc2/0x24f
    &inode->i_data.tree_lock 0 [] find_get_page+0x1a/0x58

    .................................................................................................................................................................

    proc_inum_idr.lock: 0 0.00 0.00 0.00 36 0.00 65.60 148.26
    proc_subdir_lock: 0 0.00 0.00 0.00 3049859 0.00 106.81 1563212.42
    shrinker_rwsem-W: 0 0.00 0.00 0.00 5 0.00 1.73 3.68
    shrinker_rwsem-R: 0 0.00 0.00 0.00 633 2.57 246.57 10909.76

    'contentions' and 'acquisitions' are the number of such events measured (since
    the last reset). The waittime- and holdtime- (min, max, total) numbers are
    presented in microseconds.

    If there are any contention points, the lock class is presented in the block
    format (as i_mutex and tree_lock above), otherwise a single line of output is
    presented.

    The output is sorted on absolute number of contentions (read + write), this
    should get the worst offenders presented first, so that:

    # grep : /proc/lock_stat | head

    will quickly show who's bad.

    The stats can be reset using:

    # echo 0 > /proc/lock_stat

    [bunk@stusta.de: make 2 functions static]
    [akpm@linux-foundation.org: fix printk warning]
    Signed-off-by: Peter Zijlstra
    Acked-by: Ingo Molnar
    Acked-by: Jason Baron
    Signed-off-by: Adrian Bunk
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     
  • 8e18257d2   lockdep: reduce the ifdeffery ... Browse Code »

    Move code around to get fewer but larger #ifdef sections. Break some
    in-function #ifdefs out into their own functions.

    Signed-off-by: Peter Zijlstra
    Acked-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     

15 Feb, 2007

1 commit

  • cd354f1ae   [PATCH] remove many unneeded #includes of sched.h ... Browse Code »

    After Al Viro (finally) succeeded in removing the sched.h #include in module.h
    recently, it makes sense again to remove other superfluous sched.h includes.
    There are quite a lot of files which include it but don't actually need
    anything defined in there. Presumably these includes were once needed for
    macros that used to live in sched.h, but moved to other header files in the
    course of cleaning it up.

    To ease the pain, this time I did not fiddle with any header files and only
    removed #includes from .c-files, which tend to cause less trouble.

    Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
    arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
    allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
    configs in arch/arm/configs on arm. I also checked that no new warnings were
    introduced by the patch (actually, some warnings are removed that were emitted
    by unnecessarily included header files).

    Signed-off-by: Tim Schmielau
    Acked-by: Russell King
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Tim Schmielau
     

12 Feb, 2007

2 commits

  • 501b9ebf4   [PATCH] Fix apparent typo CONFIG_LOCKDEP_DEBUG ... Browse Code »

    Replace the apparent typo CONFIG_LOCKDEP_DEBUG with the correct
    CONFIG_DEBUG_LOCKDEP.

    Signed-off-by: Robert P. J. Day
    Cc: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Robert P. J. Day
     
  • 068135e63   [PATCH] lockdep: add graph depth information to /proc/lockdep ... Browse Code »

    Generate locking graph information into /proc/lockdep, for lock hierarchy
    documentation and visualization purposes.

    sample output:

    c089fd5c OPS: 138 FD: 14 BD: 1 --..: &tty->termios_mutex
    -> [c07a3430] tty_ldisc_lock
    -> [c07a37f0] &port_lock_key
    -> [c07afdc0] &rq->rq_lock_key#2

    The lock classes listed are all the first-hop lock dependencies that
    lockdep has seen so far.

    Signed-off-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jason Baron
     

08 Dec, 2006

1 commit

04 Jul, 2006

1 commit

  • a8f24a397   [PATCH] lockdep: procfs ... Browse Code »

    Lock validator /proc/lockdep and /proc/lockdep_stats support.
    (FIXME: should go into debugfs)

    Signed-off-by: Ingo Molnar
    Signed-off-by: Arjan van de Ven
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ingo Molnar