Eric Lee / smarc-fsl-linux-kernel

13 Sep, 2011

1 commit

  • 07354eb1a   locking, printk: Annotate logbuf_lock as raw ... Browse Code »

    The logbuf_lock lock can be taken in atomic context and therefore
    cannot be preempted on -rt - annotate it.

    In mainline this change documents the low level nature of
    the lock - otherwise there's no functional difference. Lockdep
    and Sparse checking will work as usual.

    Signed-off-by: Thomas Gleixner
    [ merged and fixed it ]
    Signed-off-by: Ingo Molnar

    Thomas Gleixner
     

07 Apr, 2010

2 commits

23 Oct, 2009

1 commit

  • 5c8287133   ratelimit: Make suppressed output messages more useful ... Browse Code »

    Today I got:

    [39648.224782] Registered led device: iwl-phy0::TX
    [40676.545099] __ratelimit: 246 callbacks suppressed
    [40676.545103] abcdef[23675]: segfault at 0 ...

    as you can see the ratelimit message contains a function prefix.
    Since this is always __ratelimit, this wont help much.

    This patch changes __ratelimit and printk_ratelimit to print the
    function name that calls ratelimit.

    This will pinpoint the responsible function, as long as not several
    different places call ratelimit with the same ratelimit state at
    the same time. In that case we catch only one random function that
    calls ratelimit after the wait period.

    Signed-off-by: Christian Borntraeger
    Cc: Dave Young
    Cc: Linus Torvalds
    CC: Andrew Morton
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Christian Borntraeger
     

22 Sep, 2009

3 commits

  • 3fff4c42b   printk: Remove ratelimit.h from kernel.h ... Browse Code »

    Decouple kernel.h from ratelimit.h: the global declaration of
    printk's ratelimit_state is not needed, and it leads to messy
    circular dependencies due to ratelimit.h's (new) adding of a
    spinlock_types.h include.

    Cc: Peter Zijlstra
    Cc: Andrew Morton
    Cc: Linus Torvalds
    Cc: David S. Miller
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     
  • edaac8e31   ratelimit: Fix/allow use in atomic contexts ... Browse Code »

    I'd like to use printk_ratelimit() in NMI context, but it's not
    robust right now due to spinlock usage in lib/ratelimit.c. If an
    NMI is unlucky enough to hit just that spot we might lock up trying
    to take the spinlock again.

    Fix that by using a trylock variant. If we contend on that lock we
    can genuinely skip the message because the state is just being
    accessed by another CPU (or by this CPU).

    ( We could use atomics for the suppressed messages field, but
    i doubt it matters in practice and it makes the code heavier. )

    Cc: Peter Zijlstra
    Cc: Andrew Morton
    Cc: Linus Torvalds
    Cc: David S. Miller
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     
  • 979f693de   ratelimit: Use per ratelimit context locking ... Browse Code »

    I'd like to use printk_ratelimit() in atomic context, but that's
    not possible right now due to the spinlock usage this commit
    introduced more than a year ago:

    717115e: printk ratelimiting rewrite

    As a first step push the lock into the ratelimit state structure.
    This allows us to deal with locking failures to be considered as an
    event related to that state being too busy.

    Also clean up the code a bit (without changing functionality):

    - tidy up the definitions

    - clean up the code flow

    This also shrinks the code a tiny bit:

    text data bss dec hex filename
    264 0 4 268 10c ratelimit.o.before
    255 0 0 255 ff ratelimit.o.after

    ( Whole-kernel data size got a bit larger, because we have
    two ratelimit-state data structures right now. )

    Cc: Peter Zijlstra
    Cc: Andrew Morton
    Cc: Linus Torvalds
    Cc: David S. Miller
    LKML-Reference:
    Signed-off-by: Ingo Molnar

    Ingo Molnar
     

29 Jul, 2008

1 commit

26 Jul, 2008

1 commit

  • 717115e1a   printk ratelimiting rewrite ... Browse Code »

    All ratelimit user use same jiffies and burst params, so some messages
    (callbacks) will be lost.

    For example:
    a call printk_ratelimit(5 * HZ, 1)
    b call printk_ratelimit(5 * HZ, 1) before the 5*HZ timeout of a, then b will
    will be supressed.

    - rewrite __ratelimit, and use a ratelimit_state as parameter. Thanks for
    hints from andrew.

    - Add WARN_ON_RATELIMIT, update rcupreempt.h

    - remove __printk_ratelimit

    - use __ratelimit in net_ratelimit

    Signed-off-by: Dave Young
    Cc: "David S. Miller"
    Cc: "Paul E. McKenney"
    Cc: Dave Young
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Dave Young
     

29 Apr, 2008

1 commit

  • 5f97a5a87   isolate ratelimit from printk.c for other use ... Browse Code »

    Due to the rcupreempt.h WARN_ON trigged, I got 2G syslog file. For some
    serious complaining of kernel, we need repeat the warnings, so here I isolate
    the ratelimit part of printk.c to a standalone file.

    Signed-off-by: Dave Young
    Acked-by: Paul E. McKenney
    Tested-by: Paul E. McKenney
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Dave Young