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2009-05-07Merge branch 'linus' into tracing/coreIngo Molnar1-8/+14
Merge reason: tracing/core was on a .30-rc1 base and was missing out on on a handful of tracing fixes present in .30-rc5-almost. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-17lockdep: more robust lockdep_map init sequencePeter Zijlstra1-8/+14
Steven Rostedt reported: > OK, I think I figured this bug out. This is a lockdep issue with respect > to tracepoints. > > The trace points in lockdep are called all the time. Outside the lockdep > logic. But if lockdep were to trigger an error / warning (which this run > did) we might be in trouble. For new locks, like the dentry->d_lock, that > are created, they will not get a name: > > void lockdep_init_map(struct lockdep_map *lock, const char *name, > struct lock_class_key *key, int subclass) > { > if (unlikely(!debug_locks)) > return; > > When a problem is found by lockdep, debug_locks becomes false. Thus we > stop allocating names for locks. This dentry->d_lock I had, now has no > name. Worse yet, I have CONFIG_DEBUG_VM set, that scrambles non > initialized memory. Thus, when the trace point was hit, it had junk for > the lock->name, and the machine crashed. Ah, nice catch. I think we should put at least the name in regardless. Ensure we at least initialize the trivial entries of the depmap so that they can be relied upon, even when lockdep itself decided to pack up and go home. [ Impact: fix lock tracing after lockdep warnings. ] Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1239954049.23397.4156.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14tracing/events: move trace point headers into include/trace/eventsSteven Rostedt1-1/+1
Impact: clean up Create a sub directory in include/trace called events to keep the trace point headers in their own separate directory. Only headers that declare trace points should be defined in this directory. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14tracing: create automated trace definesSteven Rostedt1-9/+3
This patch lowers the number of places a developer must modify to add new tracepoints. The current method to add a new tracepoint into an existing system is to write the trace point macro in the trace header with one of the macros TRACE_EVENT, TRACE_FORMAT or DECLARE_TRACE, then they must add the same named item into the C file with the macro DEFINE_TRACE(name) and then add the trace point. This change cuts out the needing to add the DEFINE_TRACE(name). Every file that uses the tracepoint must still include the trace/<type>.h file, but the one C file must also add a define before the including of that file. #define CREATE_TRACE_POINTS #include <trace/mytrace.h> This will cause the trace/mytrace.h file to also produce the C code necessary to implement the trace point. Note, if more than one trace/<type>.h is used to create the C code it is best to list them all together. #define CREATE_TRACE_POINTS #include <trace/foo.h> #include <trace/bar.h> #include <trace/fido.h> Thanks to Mathieu Desnoyers and Christoph Hellwig for coming up with the cleaner solution of the define above the includes over my first design to have the C code include a "special" header. This patch converts sched, irq and lockdep and skb to use this new method. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-10tracing/lockdep: report the time waited for a lockFrederic Weisbecker1-4/+4
While trying to optimize the new lock on reiserfs to replace the bkl, I find the lock tracing very useful though it lacks something important for performance (and latency) instrumentation: the time a task waits for a lock. That's what this patch implements: bash-4816 [000] 202.652815: lock_contended: lock_contended: &sb->s_type->i_mutex_key bash-4816 [000] 202.652819: lock_acquired: &rq->lock (0.000 us) <...>-4787 [000] 202.652825: lock_acquired: &rq->lock (0.000 us) <...>-4787 [000] 202.652829: lock_acquired: &rq->lock (0.000 us) bash-4816 [000] 202.652833: lock_acquired: &sb->s_type->i_mutex_key (16.005 us) As shown above, the "lock acquired" field is followed by the time it has been waiting for the lock. Usually, a lock contended entry is followed by a near lock_acquired entry with a non-zero time waited. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1238975373-15739-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tipLinus Torvalds1-0/+5
* 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: lockdep: add stack dumps to asserts hrtimer: fix rq->lock inversion (again)
2009-04-02Merge branch 'tracing/core-v2' into tracing-for-linusIngo Molnar1-11/+22
Conflicts: include/linux/slub_def.h lib/Kconfig.debug mm/slob.c mm/slub.c
2009-03-31lockdep: add stack dumps to assertsPeter Zijlstra1-0/+5
Have a better idea about exactly which loc causes a lockdep limit overflow. Often it's a bug or inefficiency in that subsystem. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1237376327.5069.253.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31Merge branch 'linus' into locking-for-linusIngo Molnar1-2/+19
Conflicts: lib/Kconfig.debug
2009-03-30lockdep: fix deadlock in lockdep_trace_allocPeter Zijlstra1-2/+19
Heiko reported that we grab the graph lock with irqs enabled. Fix this by providng the same wrapper as all other lockdep entry functions have. Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nick Piggin <npiggin@suse.de> LKML-Reference: <1237544000.24626.52.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13Merge branch 'core/locking' into tracing/ftraceIngo Molnar1-7/+0
2009-03-05lockdep: remove duplicate CONFIG_DEBUG_LOCKDEP definitionsDavid Rientjes1-7/+0
Impact: cleanup The atomic debug modifiers are already defined in kernel/lockdep_internals.h. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <alpine.DEB.2.00.0903050222160.30401@chino.kir.corp.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04tracing: add lockdep tracepoints for lock acquire/releasePeter Zijlstra1-0/+17
Augment the traces with lock names when lockdep is available: 1) | down_read_trylock() { 1) | _spin_lock_irqsave() { 1) | /* lock_acquire: &sem->wait_lock */ 1) 4.201 us | } 1) | _spin_unlock_irqrestore() { 1) | /* lock_release: &sem->wait_lock */ 1) 3.523 us | } 1) | /* lock_acquire: try read &mm->mmap_sem */ 1) + 13.386 us | } 1) 1.635 us | find_vma(); 1) | handle_mm_fault() { 1) | __do_fault() { 1) | filemap_fault() { 1) | find_lock_page() { 1) | find_get_page() { 1) | /* lock_acquire: read rcu_read_lock */ 1) | /* lock_release: rcu_read_lock */ 1) 5.697 us | } 1) 8.158 us | } 1) + 11.079 us | } 1) | _spin_lock() { 1) | /* lock_acquire: __pte_lockptr(page) */ 1) 3.949 us | } 1) 1.460 us | page_add_file_rmap(); 1) | _spin_unlock() { 1) | /* lock_release: __pte_lockptr(page) */ 1) 3.115 us | } 1) | unlock_page() { 1) 1.421 us | page_waitqueue(); 1) 1.220 us | __wake_up_bit(); 1) 6.519 us | } 1) + 34.328 us | } 1) + 37.452 us | } 1) | up_read() { 1) | /* lock_release: &mm->mmap_sem */ 1) | _spin_lock_irqsave() { 1) | /* lock_acquire: &sem->wait_lock */ 1) 3.865 us | } 1) | _spin_unlock_irqrestore() { 1) | /* lock_release: &sem->wait_lock */ 1) 8.562 us | } 1) + 17.370 us | } Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: =?ISO-8859-1?Q?T=F6r=F6k?= Edwin <edwintorok@gmail.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1236166375.5330.7209.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04lockdep: remove extra "irq" stringPeter Zijlstra1-2/+2
Impact: clarify lockdep printk text print_irq_inversion_bug() gets handed state strings of the form "HARDIRQ", "SOFTIRQ", "RECLAIM_FS" and appends "-irq-{un,}safe" to them, which is either redudant for *IRQ or confusing in the RECLAIM_FS case. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1236175192.5330.7585.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04lockdep: fix incorrect state namePeter Zijlstra1-2/+3
In the recent mark_lock_irq() rework a bug snuck in that would report the state of write locks causing irq inversion under a read lock as a read lock. Fix this by masking the read bit of the state when validating write dependencies. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1236172646.5330.7450.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-15lockdep: build fix for !PROVE_LOCKINGPeter Zijlstra1-0/+4
The __GFP_FS annotations fail to build with CONFIG_LOCKDEP=y, CONFIG_PROVE_LOCKING=n, ammend that. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: use stringify.hPeter Zijlstra1-9/+7
Arnd pointed out we have the stringify macro magic already in-kernel. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> CC: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: simplify check_prev_add_irq()Peter Zijlstra1-93/+61
Remove the manual state iteration thingy. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: get_user_chars() redoPeter Zijlstra1-12/+12
Generic, states independent, get_user_chars(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: simplify get_user_chars()Peter Zijlstra1-41/+24
there's too much repetition of code.. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: add comments to mark_lock_irq()Peter Zijlstra1-7/+30
re-add some of the comments that got lost in the refactoring. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: remove macro usage from mark_held_locks()Peter Zijlstra1-15/+5
Now that we have nice numerical relations for the states, remove the macro magics. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: fully reduce mark_lock_irq()Peter Zijlstra1-78/+8
Now what its only two functions, they again look rather similar. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: merge the !_READ mark_lock_irq() helpersPeter Zijlstra1-43/+15
These two are also remakably similar Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: merge the _READ mark_lock_irq() helpersPeter Zijlstra1-38/+23
The _READ helpers show remarkable similarity, merge them. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: simplify mark_lock_irq() helpers #3Peter Zijlstra1-38/+27
Kill another argument Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: further simplify mark_lock_irq() helpersPeter Zijlstra1-16/+31
take away another parameter Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: simplify the mark_lock_irq() helpersPeter Zijlstra1-16/+44
In order to unify them, take some arguments away Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: split up mark_lock_irq()Peter Zijlstra1-225/+147
split mark_lock_irq() into 4 simple helper functions Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: generate usage stringsPeter Zijlstra1-13/+13
generate the usage strings XXX capital invasion :-( Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: simplify mark_lock()Peter Zijlstra1-12/+7
remove the state iteration Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: simplify mark_held_locksPeter Zijlstra1-24/+14
remove the explicit state iteration Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: sanitize reclaim bit namesPeter Zijlstra1-19/+19
s/HELD_OVER/ENABLED/g so that its similar to the hard and soft-irq names. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: sanitize bit namesPeter Zijlstra1-42/+42
s/\(LOCKF\?_ENABLED_[^ ]*\)S\(_READ\)\?\>/\1\2/g So that the USED_IN and ENABLED have the same names. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14lockdep: annotate reclaim context (__GFP_NOFS)Nick Piggin1-12/+217
Here is another version, with the incremental patch rolled up, and added reclaim context annotation to kswapd, and allocation tracing to slab allocators (which may only ever reach the page allocator in rare cases, so it is good to put annotations here too). Haven't tested this version as such, but it should be getting closer to merge worthy ;) -- After noticing some code in mm/filemap.c accidentally perform a __GFP_FS allocation when it should not have been, I thought it might be a good idea to try to catch this kind of thing with lockdep. I coded up a little idea that seems to work. Unfortunately the system has to actually be in __GFP_FS page reclaim, then take the lock, before it will mark it. But at least that might still be some orders of magnitude more common (and more debuggable) than an actual deadlock condition, so we have some improvement I hope (the concept is no less complete than discovery of a lock's interrupt contexts). I guess we could even do the same thing with __GFP_IO (normal reclaim), and even GFP_NOIO locks too... but filesystems will have the most locks and fiddly code paths, so let's start there and see how it goes. It *seems* to work. I did a quick test. ================================= [ INFO: inconsistent lock state ] 2.6.28-rc6-00007-ged31348-dirty #26 --------------------------------- inconsistent {in-reclaim-W} -> {ov-reclaim-W} usage. modprobe/8526 [HC0[0]:SC0[0]:HE1:SE1] takes: (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd] {in-reclaim-W} state was registered at: [<ffffffff80267bdb>] __lock_acquire+0x75b/0x1a60 [<ffffffff80268f71>] lock_acquire+0x91/0xc0 [<ffffffff8070f0e1>] mutex_lock_nested+0xb1/0x310 [<ffffffffa002002b>] brd_init+0x2b/0x216 [brd] [<ffffffff8020903b>] _stext+0x3b/0x170 [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0 [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff irq event stamp: 3929 hardirqs last enabled at (3929): [<ffffffff8070f2b5>] mutex_lock_nested+0x285/0x310 hardirqs last disabled at (3928): [<ffffffff8070f089>] mutex_lock_nested+0x59/0x310 softirqs last enabled at (3732): [<ffffffff8061f623>] sk_filter+0x83/0xe0 softirqs last disabled at (3730): [<ffffffff8061f5b6>] sk_filter+0x16/0xe0 other info that might help us debug this: 1 lock held by modprobe/8526: #0: (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd] stack backtrace: Pid: 8526, comm: modprobe Not tainted 2.6.28-rc6-00007-ged31348-dirty #26 Call Trace: [<ffffffff80265483>] print_usage_bug+0x193/0x1d0 [<ffffffff80266530>] mark_lock+0xaf0/0xca0 [<ffffffff80266735>] mark_held_locks+0x55/0xc0 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd] [<ffffffff802667ca>] trace_reclaim_fs+0x2a/0x60 [<ffffffff80285005>] __alloc_pages_internal+0x475/0x580 [<ffffffff8070f29e>] ? mutex_lock_nested+0x26e/0x310 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd] [<ffffffffa002006a>] brd_init+0x6a/0x216 [brd] [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd] [<ffffffff8020903b>] _stext+0x3b/0x170 [<ffffffff8070f8b9>] ? mutex_unlock+0x9/0x10 [<ffffffff8070f83d>] ? __mutex_unlock_slowpath+0x10d/0x180 [<ffffffff802669ec>] ? trace_hardirqs_on_caller+0x12c/0x190 [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0 [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-30Merge branch 'core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tipLinus Torvalds1-28/+32
* 'core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (63 commits) stacktrace: provide save_stack_trace_tsk() weak alias rcu: provide RCU options on non-preempt architectures too printk: fix discarding message when recursion_bug futex: clean up futex_(un)lock_pi fault handling "Tree RCU": scalable classic RCU implementation futex: rename field in futex_q to clarify single waiter semantics x86/swiotlb: add default swiotlb_arch_range_needs_mapping x86/swiotlb: add default phys<->bus conversion x86: unify pci iommu setup and allow swiotlb to compile for 32 bit x86: add swiotlb allocation functions swiotlb: consolidate swiotlb info message printing swiotlb: support bouncing of HighMem pages swiotlb: factor out copy to/from device swiotlb: add arch hook to force mapping swiotlb: allow architectures to override phys<->bus<->phys conversions swiotlb: add comment where we handle the overflow of a dma mask on 32 bit rcu: fix rcutorture behavior during reboot resources: skip sanity check of busy resources swiotlb: move some definitions to header swiotlb: allow architectures to override swiotlb pool allocation ... Fix up trivial conflicts in arch/x86/kernel/Makefile arch/x86/mm/init_32.c include/linux/hardirq.h as per Ingo's suggestions.
2008-12-04lockdep: change a held lock's classPeter Zijlstra1-15/+9
Impact: introduce new lockdep API Allow to change a held lock's class. Basically the same as the existing code to change a subclass therefore reuse all that. The XFS code will be able to use this to annotate their inode locking. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-04Merge commit 'v2.6.28-rc7' into core/lockingIngo Molnar1-2/+2
2008-12-03ftrace: replace raw_local_irq_save with local_irq_saveSteven Rostedt1-0/+1
Impact: fix for lockdep and ftrace The raw_local_irq_save/restore confuses lockdep. This patch converts them to the local_irq_save/restore variants. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-25lockdep: fix unused function warning in kernel/lockdep.cIngo Molnar1-1/+2
Impact: fix build warning this warning: kernel/lockdep.c:584: warning: ‘print_lock_dependencies’ defined but not used triggers because print_lock_dependencies() is only used if both CONFIG_TRACE_IRQFLAGS and CONFIG_PROVE_LOCKING are enabled. But adding #ifdefs is not an option here - it would spread out to 4-5 other helper functions and uglify the file. So mark this function as __used - it's static and the compiler can eliminate it just fine. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-21lockdep: consistent alignement for lockdep infoLi Zefan1-2/+2
Impact: prettify /proc/lockdep_info Just feel odd that not all lines of lockdep info are aligned. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-12Merge branch 'linus' into core/lockingIngo Molnar1-9/+8
2008-10-28lockdep: fix irqs on/off ip tracingHeiko Carstens1-7/+5
Impact: fix lockdep lock-api-caller output when irqsoff tracing is enabled 81d68a96 "ftrace: trace irq disabled critical timings" added wrappers around trace_hardirqs_on/off_caller. However these functions use __builtin_return_address(0) to figure out which function actually disabled or enabled irqs. The result is that we save the ips of trace_hardirqs_on/off instead of the real caller. Not very helpful. However since the patch from Steven the ip already gets passed. So use that and get rid of __builtin_return_address(0) in these two functions. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-28lockdep: minor fix for debug_show_all_locks()qinghuang feng1-2/+3
When we failed to get tasklist_lock eventually (count equals 0), we should only print " ignoring it.\n", and not print " locked it.\n" needlessly. Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-20lockstat: contend with pointsPeter Zijlstra1-12/+21
We currently only provide points that have to wait on contention, also lists the points we have to wait for. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-27lockdep: fix invalid list_del_rcu in zap_classZhu Yi1-2/+2
The problem is found during iwlagn driver testing on v2.6.27-rc4-176-gb8e6c91 kernel, but it turns out to be a lockdep bug. In our testing, we frequently load and unload the iwlagn driver (>50 times). Then the MAX_STACK_TRACE_ENTRIES is reached (expected behaviour?). The error message with the call trace is as below. BUG: MAX_STACK_TRACE_ENTRIES too low! turning off the locking correctness validator. Pid: 4895, comm: iwlagn Not tainted 2.6.27-rc4 #13 Call Trace: [<ffffffff81014aa1>] save_stack_trace+0x22/0x3e [<ffffffff8105390a>] save_trace+0x8b/0x91 [<ffffffff81054e60>] mark_lock+0x1b0/0x8fa [<ffffffff81056f71>] __lock_acquire+0x5b9/0x716 [<ffffffffa00d818a>] ieee80211_sta_work+0x0/0x6ea [mac80211] [<ffffffff81057120>] lock_acquire+0x52/0x6b [<ffffffff81045f0e>] run_workqueue+0x97/0x1ed [<ffffffff81045f5e>] run_workqueue+0xe7/0x1ed [<ffffffff81045f0e>] run_workqueue+0x97/0x1ed [<ffffffff81046ae4>] worker_thread+0xd8/0xe3 [<ffffffff81049503>] autoremove_wake_function+0x0/0x2e [<ffffffff81046a0c>] worker_thread+0x0/0xe3 [<ffffffff810493ec>] kthread+0x47/0x73 [<ffffffff8128e3ab>] trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff8100cea9>] child_rip+0xa/0x11 [<ffffffff8100c4df>] restore_args+0x0/0x30 [<ffffffff810316e1>] finish_task_switch+0x0/0xcc [<ffffffff810493a5>] kthread+0x0/0x73 [<ffffffff8100ce9f>] child_rip+0x0/0x11 Although the above is harmless, when the ilwagn module is removed later lockdep will trigger a kernel oops as below. BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: [<ffffffff810531e1>] zap_class+0x24/0x82 PGD 73128067 PUD 7448c067 PMD 0 Oops: 0002 [1] SMP CPU 0 Modules linked in: rfcomm l2cap bluetooth autofs4 sunrpc nf_conntrack_ipv6 xt_state nf_conntrack xt_tcpudp ip6t_ipv6header ip6t_REJECT ip6table_filter ip6_tables x_tables ipv6 cpufreq_ondemand acpi_cpufreq dm_mirror dm_log dm_multipath dm_mod snd_hda_intel sr_mod snd_seq_dummy snd_seq_oss snd_seq_midi_event battery snd_seq snd_seq_device cdrom button snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd_page_alloc e1000e snd_hwdep sg iTCO_wdt iTCO_vendor_support ac pcspkr i2c_i801 i2c_core snd soundcore video output ata_piix ata_generic libata sd_mod scsi_mod ext3 jbd mbcache uhci_hcd ohci_hcd ehci_hcd [last unloaded: mac80211] Pid: 4941, comm: modprobe Not tainted 2.6.27-rc4 #10 RIP: 0010:[<ffffffff810531e1>] [<ffffffff810531e1>] zap_class+0x24/0x82 RSP: 0000:ffff88007bcb3eb0 EFLAGS: 00010046 RAX: 0000000000068ee8 RBX: ffffffff8192a0a0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000001dfb RDI: ffffffff816e70b0 RBP: ffffffffa00cd000 R08: ffffffff816818f8 R09: ffff88007c923558 R10: ffffe20002ad2408 R11: ffffffff811028ec R12: ffffffff8192a0a0 R13: 000000000002bd90 R14: 0000000000000000 R15: 0000000000000296 FS: 00007f9d1cee56f0(0000) GS:ffffffff814a58c0(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000008 CR3: 0000000073047000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process modprobe (pid: 4941, threadinfo ffff88007bcb2000, task ffff8800758d1fc0) Stack: ffffffff81057376 0000000000000000 ffffffffa00f7b00 0000000000000000 0000000000000080 0000000000618278 00007fff24f16720 0000000000000000 ffffffff8105d37a ffffffffa00f7b00 ffffffff8105d591 313132303863616d Call Trace: [<ffffffff81057376>] ? lockdep_free_key_range+0x61/0xf5 [<ffffffff8105d37a>] ? free_module+0xd4/0xe4 [<ffffffff8105d591>] ? sys_delete_module+0x1de/0x1f9 [<ffffffff8106dbfa>] ? audit_syscall_entry+0x12d/0x160 [<ffffffff8100be2b>] ? system_call_fastpath+0x16/0x1b Code: b2 00 01 00 00 00 c3 31 f6 49 c7 c0 10 8a 61 81 eb 32 49 39 38 75 26 48 98 48 6b c0 38 48 8b 90 08 8a 61 81 48 8b 88 00 8a 61 81 <48> 89 51 08 48 89 0a 48 c7 80 08 8a 61 81 00 02 20 00 48 ff c6 RIP [<ffffffff810531e1>] zap_class+0x24/0x82 RSP <ffff88007bcb3eb0> CR2: 0000000000000008 ---[ end trace a1297e0c4abb0f2e ]--- The root cause for this oops is in add_lock_to_list() when save_trace() fails due to MAX_STACK_TRACE_ENTRIES is reached, entry->class is assigned but entry is never added into any lock list. This makes the list_del_rcu() in zap_class() oops later when the module is unloaded. This patch fixes the problem by assigning entry->class after save_trace() returns success. Signed-off-by: Zhu Yi <yi.zhu@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-26lockstat: repair erronous contention statisticsJoe Korty1-1/+1
Fix bad contention counting in /proc/lock_stat. /proc/lockstat tries to gather per-ip contention statistics per-lock. This was failing due to a garbage per-ip index selector being used. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-18lockdep: fix spurious 'inconsistent lock state' warningDmitry Baryshkov1-1/+1
Since f82b217e3513fe3af342c0f3ee1494e86250c21c lockdep can output spurious warnings related to hwirqs due to hardirq_off shrinkage from int to bit-sized flag. Guard it with double negation to fix the warning. Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-13lockdep: use WARN() in kernel/lockdep.cArjan van de Ven1-4/+2
Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes part of the warning section for better reporting/collection. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2008-08-11lockdep: fix debug_lock_allocPeter Zijlstra1-6/+0
When we enable DEBUG_LOCK_ALLOC but do not enable PROVE_LOCKING and or LOCK_STAT, lock_alloc() and lock_release() turn into nops, even though we should be doing hlock checking (check=1). This causes a false warning and a lockdep self-disable. Rectify this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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