Eric Lee / smarc-fsl-linux-kernel

17 Jul, 2007

1 commit

  • e1f4a88c5   introduce write_trylock_irqsave() ... Browse Code »

    Introduce a write_trylock_irqsave() implementation. Similar in style to
    the implementation of spin_trylock_irqsave() in mainline.

    Signed-off-by: Satyam Sharma
    Cc: Sripathi Kodi
    Cc: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Satyam Sharma
     

05 Mar, 2007

1 commit

  • e81ce1f7e   [PATCH] timer/hrtimer: take per cpu locks in sane order ... Browse Code »

    Doing something like this on a two cpu system

    # echo 0 > /sys/devices/system/cpu/cpu0/online
    # echo 1 > /sys/devices/system/cpu/cpu0/online
    # echo 0 > /sys/devices/system/cpu/cpu1/online

    will give me this:

    =======================================================
    [ INFO: possible circular locking dependency detected ]
    2.6.21-rc2-g562aa1d4-dirty #7
    -------------------------------------------------------
    bash/1282 is trying to acquire lock:
    (&cpu_base->lock_key){.+..}, at: [] hrtimer_cpu_notify+0xc6/0x240

    but task is already holding lock:
    (&cpu_base->lock_key#2){.+..}, at: [] hrtimer_cpu_notify+0xbc/0x240

    which lock already depends on the new lock.

    This happens because we have the following code in kernel/hrtimer.c:

    migrate_hrtimers(int cpu)
    [...]
    old_base = &per_cpu(hrtimer_bases, cpu);
    new_base = &get_cpu_var(hrtimer_bases);
    [...]
    spin_lock(&new_base->lock);
    spin_lock(&old_base->lock);

    Which means the spinlocks are taken in an order which depends on which cpu
    gets shut down from which other cpu. Therefore lockdep complains that there
    might be an ABBA deadlock. Since migrate_hrtimers() gets only called on
    cpu hotplug it's safe to assume that it isn't executed concurrently on a

    The same problem exists in kernel/timer.c: migrate_timers().

    As pointed out by Christian Borntraeger one possible solution to avoid
    the locking order complaints would be to make sure that the locks are
    always taken in the same order. E.g. by taking the lock of the cpu with
    the lower number first.

    To achieve this we introduce two new spinlock functions double_spin_lock
    and double_spin_unlock which lock or unlock two locks in a given order.

    Cc: Ingo Molnar
    Cc: Thomas Gleixner
    Cc: Roman Zippel
    Cc: John Stultz
    Cc: Christian Borntraeger
    Cc: Martin Schwidefsky
    Signed-off-by: Heiko Carstens
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Heiko Carstens
     

12 Feb, 2007

1 commit

08 Dec, 2006

1 commit

  • 676dcb8bc   [PATCH] add bottom_half.h ... Browse Code »

    With CONFIG_SMP=n:

    drivers/input/ff-memless.c:384: warning: implicit declaration of function 'local_bh_disable'
    drivers/input/ff-memless.c:393: warning: implicit declaration of function 'local_bh_enable'

    Really linux/spinlock.h should include linux/interrupt.h. But interrupt.h
    includes sched.h which will need spinlock.h.

    So the patch breaks the _bh declarations out into a separate header and
    includes it in both interrupt.h and spinlock.h.

    Cc: "Randy.Dunlap"
    Cc: Andi Kleen
    Cc:
    Cc: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrew Morton
     

27 Nov, 2006

1 commit

  • b8e6ec865   Revert "[PATCH] Enforce "unsigned long flags;" when spinlocking" ... Browse Code »

    This reverts commit ee3ce191e8eaa4cc15c51a28b34143b36404c4f5, since it
    broke on at least ARM, MIPS and PA-RISC due to complicated header file
    dependencies.

    Conflicts in include/linux/spinlock.h (due to the "nested" variety
    fixes) fixed up by hand.

    Cc: Alexey Dobriyan
    Cc: Ralf Baechle
    Cc: Kyle McMartin
    Cc: Russell King
    Signed-off-by: Linus Torvalds

    Linus Torvalds
     

26 Nov, 2006

2 commits

  • cfd3ef234   [PATCH] lockdep: spin_lock_irqsave_nested() ... Browse Code »

    Introduce spin_lock_irqsave_nested(); implementation from:
    http://lkml.org/lkml/2006/6/1/122
    Patch from:
    http://lkml.org/lkml/2006/9/13/258

    [akpm@osdl.org: two compile fixes]
    Signed-off-by: Arjan van de Ven
    Signed-off-by: Jiri Kosina
    Signed-off-by: Peter Zijlstra
    Acked-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arjan van de Ven
     
  • ee3ce191e   [PATCH] Enforce "unsigned long flags;" when spinlocking ... Browse Code »

    Make it break or warn if you pass to spin_lock_irqsave() and friends
    something different from "unsigned long flags;". Suprisingly large amount
    of these was caught by recent commit
    c53421b18f205c5f97c604ae55c6a921f034b0f6 and others.

    Idea is largely from FRV typechecking. Suggestions from Andrew Morton.
    All stupid typos in first version fixed.

    Passes allmodconfig on i386, x86_64, alpha, arm as well as my usual config.

    Note #1: checking with sparse is still needed, because a driver can save
    and pass around flags or something. So far patch is very intrusive.
    Note #2: techically, we should break only if
    sizeof(flags) < sizeof(unsigned long),
    however, the more pain for getting suspicious code into kernel,
    the better.

    Signed-off-by: Alexey Dobriyan
    Cc: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alexey Dobriyan
     

30 Sep, 2006

2 commits

04 Jul, 2006

1 commit

26 Apr, 2006

1 commit

26 Dec, 2005

1 commit

  • f83b5e323   kbuild: set correct KBUILD_MODNAME when using well known kernel symbols as module names ... Browse Code »

    This patch fixes a problem when we use well known kernel symbols as module
    names.

    For example, if module source name is current.c, idle_stack.c or etc.,
    we have a bad KBUILD_MODNAME value.
    For example, KBUILD_MODNAME will be "get_current()" instead of "current", or
    "(init_thread_union.stack)" instead of "idle_task".

    The trick is to define a stringify macro on the commandline - named
    KBUILD_STR for namespace reasons - and then to stringify the module
    name.

    There are a few uses of KBUILD_MODNAME throughout the tree but the usage
    is for debug and will not be harmed by this change so left untouched for now.

    While at it KBUILD_BASENAME was changed too. Any spinlock usage in the
    unix module would have created wrong section names without it.
    Usage in spinlock.h fixed so it no longer stringify KBUILD_BASENAME.

    Original patch from Ustyogov Roman - all bugs introduced by me.

    Signed-off-by: Sam Ravnborg

    Ustyugov Roman
     

31 Oct, 2005

1 commit

11 Sep, 2005

1 commit

  • fb1c8f93d   [PATCH] spinlock consolidation ... Browse Code »

    This patch (written by me and also containing many suggestions of Arjan van
    de Ven) does a major cleanup of the spinlock code. It does the following
    things:

    - consolidates and enhances the spinlock/rwlock debugging code

    - simplifies the asm/spinlock.h files

    - encapsulates the raw spinlock type and moves generic spinlock
    features (such as ->break_lock) into the generic code.

    - cleans up the spinlock code hierarchy to get rid of the spaghetti.

    Most notably there's now only a single variant of the debugging code,
    located in lib/spinlock_debug.c. (previously we had one SMP debugging
    variant per architecture, plus a separate generic one for UP builds)

    Also, i've enhanced the rwlock debugging facility, it will now track
    write-owners. There is new spinlock-owner/CPU-tracking on SMP builds too.
    All locks have lockup detection now, which will work for both soft and hard
    spin/rwlock lockups.

    The arch-level include files now only contain the minimally necessary
    subset of the spinlock code - all the rest that can be generalized now
    lives in the generic headers:

    include/asm-i386/spinlock_types.h | 16
    include/asm-x86_64/spinlock_types.h | 16

    I have also split up the various spinlock variants into separate files,
    making it easier to see which does what. The new layout is:

    SMP | UP
    ----------------------------|-----------------------------------
    asm/spinlock_types_smp.h | linux/spinlock_types_up.h
    linux/spinlock_types.h | linux/spinlock_types.h
    asm/spinlock_smp.h | linux/spinlock_up.h
    linux/spinlock_api_smp.h | linux/spinlock_api_up.h
    linux/spinlock.h | linux/spinlock.h

    /*
    * here's the role of the various spinlock/rwlock related include files:
    *
    * on SMP builds:
    *
    * asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
    * initializers
    *
    * linux/spinlock_types.h:
    * defines the generic type and initializers
    *
    * asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel
    * implementations, mostly inline assembly code
    *
    * (also included on UP-debug builds:)
    *
    * linux/spinlock_api_smp.h:
    * contains the prototypes for the _spin_*() APIs.
    *
    * linux/spinlock.h: builds the final spin_*() APIs.
    *
    * on UP builds:
    *
    * linux/spinlock_type_up.h:
    * contains the generic, simplified UP spinlock type.
    * (which is an empty structure on non-debug builds)
    *
    * linux/spinlock_types.h:
    * defines the generic type and initializers
    *
    * linux/spinlock_up.h:
    * contains the __raw_spin_*()/etc. version of UP
    * builds. (which are NOPs on non-debug, non-preempt
    * builds)
    *
    * (included on UP-non-debug builds:)
    *
    * linux/spinlock_api_up.h:
    * builds the _spin_*() APIs.
    *
    * linux/spinlock.h: builds the final spin_*() APIs.
    */

    All SMP and UP architectures are converted by this patch.

    arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
    crosscompilers. m32r, mips, sh, sparc, have not been tested yet, but should
    be mostly fine.

    From: Grant Grundler

    Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU).
    Builds 32-bit SMP kernel (not booted or tested). I did not try to build
    non-SMP kernels. That should be trivial to fix up later if necessary.

    I converted bit ops atomic_hash lock to raw_spinlock_t. Doing so avoids
    some ugly nesting of linux/*.h and asm/*.h files. Those particular locks
    are well tested and contained entirely inside arch specific code. I do NOT
    expect any new issues to arise with them.

    If someone does ever need to use debug/metrics with them, then they will
    need to unravel this hairball between spinlocks, atomic ops, and bit ops
    that exist only because parisc has exactly one atomic instruction: LDCW
    (load and clear word).

    From: "Luck, Tony"

    ia64 fix

    Signed-off-by: Ingo Molnar
    Signed-off-by: Arjan van de Ven
    Signed-off-by: Grant Grundler
    Cc: Matthew Wilcox
    Signed-off-by: Hirokazu Takata
    Signed-off-by: Mikael Pettersson
    Signed-off-by: Benoit Boissinot
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ingo Molnar
     

22 May, 2005

1 commit

  • 10f02d1c5   [PATCH] spin_unlock_bh() and preempt_check_resched() ... Browse Code »

    In _spin_unlock_bh(lock):
    do { \
    _raw_spin_unlock(lock); \
    preempt_enable(); \
    local_bh_enable(); \
    __release(lock); \
    } while (0)

    there is no reason for using preempt_enable() instead of a simple
    preempt_enable_no_resched()

    Since we know bottom halves are disabled, preempt_schedule() will always
    return at once (preempt_count!=0), and hence preempt_check_resched() is
    useless here...

    This fixes it by using "preempt_enable_no_resched()" instead of the
    "preempt_enable()", and thus avoids the useless preempt_check_resched()
    just before re-enabling bottom halves.

    Signed-off-by: Samuel Thibault
    Signed-off-by: Linus Torvalds

    Samuel Thibault
     

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds