01 Nov, 2011
1 commit
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When SPIN_BUG_ON is triggered, the lock owner information is reported.
But it is omitted when spinlock lockup is detected.This information is useful especially on the architectures which don't
implement trigger_all_cpu_backtrace() that is called just after detecting
lockup. So report it and also avoid message format duplication.Signed-off-by: Akinobu Mita
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Dec, 2009
7 commits
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The name space hierarchy for the internal lock functions is now a bit
backwards. raw_spin* functions map to _spin* which use __spin*, while
we would like to have _raw_spin* and __raw_spin*._raw_spin* is already used by lock debugging, so rename those funtions
to do_raw_spin* to free up the _raw_spin* name space.No functional change.
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: Ingo Molnar -
Now that the raw_spin name space is freed up, we can implement
raw_spinlock and the related functions which are used to annotate the
locks which are not converted to sleeping spinlocks in preempt-rt.A side effect is that only such locks can be used with the low level
lock fsunctions which circumvent lockdep.For !rt spin_* functions are mapped to the raw_spin* implementations.
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: Ingo Molnar -
Name space cleanup for rwlock functions. No functional change.
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: David S. Miller
Acked-by: Ingo Molnar
Cc: linux-arch@vger.kernel.org -
Not strictly necessary for -rt as -rt does not have non sleeping
rwlocks, but it's odd to not have a consistent naming convention.No functional change.
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: David S. Miller
Acked-by: Ingo Molnar
Cc: linux-arch@vger.kernel.org -
Name space cleanup. No functional change.
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: David S. Miller
Acked-by: Ingo Molnar
Cc: linux-arch@vger.kernel.org -
Further name space cleanup. No functional change
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: David S. Miller
Acked-by: Ingo Molnar
Cc: linux-arch@vger.kernel.org -
The raw_spin* namespace was taken by lockdep for the architecture
specific implementations. raw_spin_* would be the ideal name space for
the spinlocks which are not converted to sleeping locks in preempt-rt.Linus suggested to convert the raw_ to arch_ locks and cleanup the
name space instead of using an artifical name like core_spin,
atomic_spin or whateverNo functional change.
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: David S. Miller
Acked-by: Ingo Molnar
Cc: linux-arch@vger.kernel.org
20 Oct, 2007
1 commit
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The task_struct->pid member is going to be deprecated, so start
using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in
the kernel.The first thing to start with is the pid, printed to dmesg - in
this case we may safely use task_pid_nr(). Besides, printks produce
more (much more) than a half of all the explicit pid usage.[akpm@linux-foundation.org: git-drm went and changed lots of stuff]
Signed-off-by: Pavel Emelyanov
Cc: Dave Airlie
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Dec, 2006
1 commit
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When a spinlock lockup occurs, arrange for the NMI code to emit an all-cpu
backtrace, so we get to see which CPU is holding the lock, and where.Cc: Andi Kleen
Cc: Ingo Molnar
Cc: Badari Pulavarty
Signed-off-by: Andrew Morton
Signed-off-by: Andi Kleen
11 Oct, 2006
1 commit
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This annotation makes it possible to assign a subclass on lock init. This
annotation is meant to reduce the _nested() annotations by assigning a
default subclass.One could do without this annotation and rely on lockdep_set_class()
exclusively, but that would require a manual stack of struct lock_class_key
objects.Signed-off-by: Peter Zijlstra
Signed-off-by: Dmitry Torokhov
30 Sep, 2006
1 commit
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In spinlock_debug.c, the spinloops call __delay() on every iteration.
Because that is an external function, (jiffies_per_loop * HZ), the loop's
iteration limit, gets recomputed every time. Caching it explicitly
prevents that.Signed-off-by: Chuck Ebbert
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Aug, 2006
1 commit
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We've confirmed that the debug version of write_lock() can get stuck for long
enough to cause NMI watchdog timeouts and hence a crash.We don't know why, yet. Disable it for now.
Also disable the similar read_lock() code. Just in case.
Thanks to Dave Olson for reporting and testing.
Acked-by: Ingo Molnar
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Jul, 2006
2 commits
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Use the lock validator framework to prove spinlock and rwlock locking
correctness.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Generic lock debugging:
- generalized lock debugging framework. For example, a bug in one lock
subsystem turns off debugging in all lock subsystems.- got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from
the mutex/rtmutex debugging code: it caused way too much prototype
hackery, and lockdep will give the same information anyway.- ability to do silent tests
- check lock freeing in vfree too.
- more finegrained debugging options, to allow distributions to
turn off more expensive debugging features.There's no separate 'held mutexes' list anymore - but there's a 'held locks'
stack within lockdep, which unifies deadlock detection across all lock
classes. (this is independent of the lockdep validation stuff - lockdep first
checks whether we are holding a lock already)Here are the current debugging options:
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=ywhich do:
config DEBUG_MUTEXES
bool "Mutex debugging, basic checks"config DEBUG_LOCK_ALLOC
bool "Detect incorrect freeing of live mutexes"Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Jul, 2006
1 commit
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Signed-off-by: Jörn Engel
Signed-off-by: Adrian Bunk
08 Feb, 2006
1 commit
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The spinlock-debug wait-loop was using loops_per_jiffy to detect too long
spinlock waits - but on fast CPUs this led to a way too fast timeout and false
messages.The fix is to include a __delay(1) call in the loop, to correctly approximate
the intended delay timeout of 1 second. The code assumes that every
architecture implements __delay(1) to last around 1/(loops_per_jiffy*HZ)
seconds.Signed-off-by: Ingo Molnar
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jan, 2006
1 commit
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Signed-off-by: Dave Jones
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Dec, 2005
1 commit
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When a spinlock debugging check hits, we print the CPU number as an
informational thing - but there is no guarantee that preemption is off
at that point - hence we should use raw_smp_processor_id(). Otherwise
DEBUG_PREEMPT will print a warning.With this fix the warning goes away and only the spinlock-debugging info
is printed.Signed-off-by: Ingo Molnar
Signed-off-by: Linus Torvalds
11 Sep, 2005
1 commit
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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 | 16I 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