The patch titled
better lock debugging: remove mutex deadlock checking code
has been added to the -mm tree. Its filename is
better-lock-debugging-remove-mutex-deadlock-checking-code.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: better lock debugging: remove mutex deadlock checking code
From: Ingo Molnar <mingo@xxxxxxx>
With the lock validator we detect mutex deadlocks (and more), the mutex
deadlock checking code is both redundant and slower. So remove it.
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/mutex-debug.c | 126 -----------------------------------------
lib/Kconfig.debug | 8 --
2 files changed, 1 insertion(+), 133 deletions(-)
diff -puN kernel/mutex-debug.c~better-lock-debugging-remove-mutex-deadlock-checking-code kernel/mutex-debug.c
--- devel/kernel/mutex-debug.c~better-lock-debugging-remove-mutex-deadlock-checking-code 2006-06-06 07:09:25.000000000 -0700
+++ devel-akpm/kernel/mutex-debug.c 2006-06-06 07:09:25.000000000 -0700
@@ -24,128 +24,6 @@
#include "mutex-debug.h"
-static void printk_task(struct task_struct *p)
-{
- if (p)
- printk("%16s:%5d [%p, %3d]", p->comm, p->pid, p, p->prio);
- else
- printk("<none>");
-}
-
-static void printk_ti(struct thread_info *ti)
-{
- if (ti)
- printk_task(ti->task);
- else
- printk("<none>");
-}
-
-static void printk_lock(struct mutex *lock, int print_owner)
-{
-#ifdef CONFIG_PROVE_MUTEX_LOCKING
- printk(" [%p] {%s}\n", lock, lock->dep_map.name);
-#else
- printk(" [%p]\n", lock);
-#endif
-
- if (print_owner && lock->owner) {
- printk(".. held by: ");
- printk_ti(lock->owner);
- printk("\n");
- }
-}
-
-static void report_deadlock(struct task_struct *task, struct mutex *lock,
- struct mutex *lockblk)
-{
- printk("\n%s/%d is trying to acquire this lock:\n",
- current->comm, current->pid);
- printk_lock(lock, 1);
- debug_show_held_locks(current);
-
- if (lockblk) {
- printk("but %s/%d is deadlocking current task %s/%d!\n\n",
- task->comm, task->pid, current->comm, current->pid);
- printk("\n%s/%d is blocked on this lock:\n",
- task->comm, task->pid);
- printk_lock(lockblk, 1);
-
- debug_show_held_locks(task);
-
- printk("\n%s/%d's [blocked] stackdump:\n\n",
- task->comm, task->pid);
- show_stack(task, NULL);
- }
-
- printk("\n%s/%d's [current] stackdump:\n\n",
- current->comm, current->pid);
- dump_stack();
- debug_show_all_locks();
- printk("[ turning off deadlock detection. Please report this. ]\n\n");
- local_irq_disable();
-}
-
-/*
- * Recursively check for mutex deadlocks:
- */
-static int check_deadlock(struct mutex *lock, int depth, struct thread_info *ti)
-{
- struct mutex *lockblk;
- struct task_struct *task;
-
- if (!debug_locks)
- return 0;
-
- ti = lock->owner;
- if (!ti)
- return 0;
-
- task = ti->task;
- /*
- * In the PROVE_MUTEX_LOCKING we are tracking all held
- * locks already, which allows us to optimize this:
- */
-#ifdef CONFIG_PROVE_MUTEX_LOCKING
- if (!task->lockdep_depth)
- return 0;
-#endif
- lockblk = NULL;
- if (task->blocked_on)
- lockblk = task->blocked_on->lock;
-
- /* Self-deadlock: */
- if (current == task) {
- debug_locks_off();
- if (depth)
- return 1;
- printk("\n==========================================\n");
- printk( "[ BUG: lock recursion deadlock detected! |\n");
- printk( "------------------------------------------\n");
- report_deadlock(task, lock, NULL);
- return 0;
- }
-
- /* Ugh, something corrupted the lock data structure? */
- if (depth > 20) {
- debug_locks_off();
- printk("\n===========================================\n");
- printk( "[ BUG: infinite lock dependency detected!? |\n");
- printk( "-------------------------------------------\n");
- report_deadlock(task, lock, lockblk);
- return 0;
- }
-
- /* Recursively check for dependencies: */
- if (lockblk && check_deadlock(lockblk, depth+1, ti)) {
- printk("\n============================================\n");
- printk( "[ BUG: circular locking deadlock detected! ]\n");
- printk( "--------------------------------------------\n");
- report_deadlock(task, lock, lockblk);
- return 0;
- }
- return 0;
-}
-
/*
* Must be called with lock->wait_lock held.
*/
@@ -179,9 +57,7 @@ void debug_mutex_add_waiter(struct mutex
struct thread_info *ti)
{
SMP_DEBUG_WARN_ON(!spin_is_locked(&lock->wait_lock));
-#ifdef CONFIG_DEBUG_MUTEX_DEADLOCKS
- check_deadlock(lock, 0, ti);
-#endif
+
/* Mark the current thread as blocked on the lock: */
ti->task->blocked_on = waiter;
waiter->lock = lock;
diff -puN lib/Kconfig.debug~better-lock-debugging-remove-mutex-deadlock-checking-code lib/Kconfig.debug
--- devel/lib/Kconfig.debug~better-lock-debugging-remove-mutex-deadlock-checking-code 2006-06-06 07:09:25.000000000 -0700
+++ devel-akpm/lib/Kconfig.debug 2006-06-06 07:09:25.000000000 -0700
@@ -133,14 +133,6 @@ config DEBUG_MUTEX_ALLOC
(kfree(), kmem_cache_free(), free_pages(), vfree(), etc.),
or whether there is any lock held during task exit.
-config DEBUG_MUTEX_DEADLOCKS
- bool "Detect mutex related deadlocks"
- default y
- depends on DEBUG_MUTEXES
- help
- This feature will automatically detect and report mutex related
- deadlocks, as they happen.
-
config DEBUG_RT_MUTEXES
bool "RT Mutex debugging, deadlock detection"
default y
_
Patches currently in -mm which might be from mingo@xxxxxxx are
git-acpi.patch
fix-drivers-mfd-ucb1x00-corec-irq-probing-bug.patch
ieee1394-semaphore-to-mutex-conversion.patch
git-infiniband.patch
git-netdev-all.patch
lock-validator-fix-ns83820c-irq-flags-bug.patch
lock-validator-fix-ns83820c-irq-flags-bug-part.patch
lock-validator-fix-ns83820c-irq-flags-part-3.patch
ipw2200-locking-fix.patch
revert-gregkh-pci-pci-test-that-drivers-properly-call-pci_set_master.patch
fall-back-to-old-style-call-trace-if-no-unwinding.patch
allow-unwinder-to-build-without-module-support.patch
lock-validator-lockdep-small-xfs-init_rwsem-cleanup.patch
swapless-pm-add-r-w-migration-entries.patch
mm-slabc-fix-early-init-assumption.patch
i386-break-out-of-recursion-in-stackframe-walk.patch
x86-re-enable-generic-numa.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-tidy.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-arch_vma_name-fix.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-vs-x86_64-mm-reliable-stack-trace-support-i386.patch
vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-vs-x86_64-mm-reliable-stack-trace-support-i386-2.patch
powerpc-vdso-updates.patch
work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs.patch
kernel-kernel-cpuc-to-mutexes.patch
cond-resched-might-sleep-fix.patch
define-__raw_get_cpu_var-and-use-it.patch
ide-cd-end-of-media-error-fix.patch
spin-rwlock-init-cleanups.patch
inotify-split-kernel-api-from-userspace-support.patch
lock-validator-introduce-warn_on_oncecond.patch
lock-validator-introduce-warn_on_oncecond-speedup.patch
emu10k1-mark-midi_spinlock-as-used.patch
epoll-use-unlocked-wqueue-operations.patch
fix-irqpoll-to-honor-disable_irq.patch
time-clocksource-infrastructure.patch
sched-fix-smt-nice-lock-contention-and-optimization.patch
sched-fix-smt-nice-lock-contention-and-optimization-tidy.patch
sched-comment-bitmap-size-accounting.patch
sched-fix-interactive-ceiling-code.patch
sched-implement-smpnice.patch
sched-protect-calculation-of-max_pull-from-integer-wrap.patch
sched-store-weighted-load-on-up.patch
sched-add-discrete-weighted-cpu-load-function.patch
sched-prevent-high-load-weight-tasks-suppressing-balancing.patch
sched-improve-stability-of-smpnice-load-balancing.patch
sched-improve-smpnice-load-balancing-when-load-per-task.patch
smpnice-dont-consider-sched-groups-which-are-lightly-loaded-for-balancing.patch
smpnice-dont-consider-sched-groups-which-are-lightly-loaded-for-balancing-fix.patch
sched-modify-move_tasks-to-improve-load-balancing-outcomes.patch
sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks.patch
sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks-fix-2.patch
sched_domain-handle-kmalloc-failure.patch
sched_domain-handle-kmalloc-failure-fix.patch
sched_domain-dont-use-gfp_atomic.patch
sched_domain-use-kmalloc_node.patch
sched_domain-allocate-sched_group-structures-dynamically.patch
sched-add-above-background-load-function.patch
mm-implement-swap-prefetching-fix.patch
pi-futex-futex-code-cleanups.patch
pi-futex-robust-futex-docs-fix.patch
pi-futex-introduce-debug_check_no_locks_freed.patch
pi-futex-introduce-warn_on_smp.patch
pi-futex-add-plist-implementation.patch
pi-futex-scheduler-support-for-pi.patch
pi-futex-rt-mutex-core.patch
pi-futex-rt-mutex-docs.patch
pi-futex-rt-mutex-docs-update.patch
pi-futex-rt-mutex-debug.patch
pi-futex-rt-mutex-tester.patch
pi-futex-rt-mutex-futex-api.patch
pi-futex-futex_lock_pi-futex_unlock_pi-support.patch
futex_requeue-optimization.patch
fix-ide-deadlock-in-error-reporting-code.patch
genirq-rename-desc-handler-to-desc-chip.patch
genirq-rename-desc-handler-to-desc-chip-power-fix.patch
genirq-rename-desc-handler-to-desc-chip-ia64-fix.patch
genirq-rename-desc-handler-to-desc-chip-ia64-fix-2.patch
genirq-sem2mutex-probe_sem-probing_active.patch
genirq-cleanup-merge-irq_affinity-into-irq_desc.patch
genirq-cleanup-remove-irq_descp.patch
genirq-cleanup-remove-irq_descp-fix.patch
genirq-cleanup-remove-fastcall.patch
genirq-cleanup-misc-code-cleanups.patch
genirq-cleanup-reduce-irq_desc_t-use-mark-it-obsolete.patch
genirq-cleanup-include-linux-irqh.patch
genirq-cleanup-merge-irq_dir-smp_affinity_entry-into-irq_desc.patch
genirq-cleanup-merge-pending_irq_cpumask-into-irq_desc.patch
genirq-cleanup-turn-arch_has_irq_per_cpu-into-config_irq_per_cpu.patch
genirq-debug-better-debug-printout-in-enable_irq.patch
genirq-add-retrigger-irq-op-to-consolidate-hw_irq_resend.patch
genirq-doc-comment-include-linux-irqh-structures.patch
genirq-doc-handle_irq_event-and-__do_irq-comments.patch
genirq-cleanup-no_irq_type-cleanups.patch
genirq-doc-add-design-documentation.patch
genirq-add-genirq-sw-irq-retrigger.patch
genirq-add-irq_noprobe-support.patch
genirq-add-irq_norequest-support.patch
genirq-add-irq_noautoen-support.patch
genirq-update-copyrights.patch
genirq-core.patch
genirq-msi-fixes-2.patch
genirq-add-irq-chip-support.patch
genirq-add-irq-chip-support-fix.patch
genirq-add-handle_bad_irq.patch
genirq-add-irq-wake-power-management-support.patch
genirq-add-sa_trigger-support.patch
genirq-cleanup-no_irq_type-no_irq_chip-rename.patch
genirq-convert-the-x86_64-architecture-to-irq-chips.patch
genirq-convert-the-i386-architecture-to-irq-chips.patch
genirq-convert-the-i386-architecture-to-irq-chips-fix-2.patch
genirq-more-verbose-debugging-on-unexpected-irq-vectors.patch
genirq-add-chip-eoi-fastack-fasteoi.patch
genirq-add-chip-eoi-fastack-fasteoi-fix.patch
lock-validator-sparc64-sparc-m68k-alpha-cris-build-fix.patch
lock-validator-floppyc-irq-release-fix.patch
lock-validator-floppyc-irq-release-fix-fix.patch
lock-validator-floppyc-irq-release-fix-fix-fix.patch
lock-validator-forcedethc-fix.patch
lock-validator-mutex-section-binutils-workaround.patch
lock-validator-add-__module_address-method.patch
lock-validator-better-lock-debugging.patch
lock-validator-locking-api-self-tests.patch
lock-validator-locking-api-self-tests-self-test-fix.patch
lock-validator-locking-init-debugging-improvement.patch
lock-validator-beautify-x86_64-stacktraces.patch
lock-validator-beautify-x86_64-stacktraces-fix.patch
lock-validator-beautify-x86_64-stacktraces-fix-2.patch
lock-validator-beautify-x86_64-stacktraces-fix-3.patch
lock-validator-beautify-x86_64-stacktraces-fix-4.patch
lock-validator-x86_64-document-stack-frame-internals.patch
lock-validator-stacktrace.patch
lock-validator-stacktrace-build-fix.patch
lock-validator-stacktrace-warning-fix.patch
lock-validator-stacktrace-fix-on-x86_64.patch
lock-validator-fown-locking-workaround.patch
lock-validator-sk_callback_lock-workaround.patch
lock-validator-irqtrace-core.patch
lock-validator-irqtrace-core-powerpc-fix-1.patch
lock-validator-irqtrace-core-non-x86-fix.patch
lock-validator-irqtrace-core-non-x86-fix-2.patch
lock-validator-irqtrace-core-non-x86-fix-3.patch
lock-validator-irqtrace-entrys-fix.patch
lock-validator-irqtrace-core-remove-softirqc-warn_on.patch
lock-validator-irqtrace-cleanup-include-asm-i386-irqflagsh.patch
lock-validator-irqtrace-cleanup-include-asm-x86_64-irqflagsh.patch
lock-validator-x86_64-irqflags-trace-entrys-fix.patch
lock-validator-lockdep-add-local_irq_enable_in_hardirq-api.patch
lock-validator-add-per_cpu_offset.patch
lock-validator-add-per_cpu_offset-fix.patch
lock-validator-core.patch
lock-validator-core-early_boot_irqs_-build-fix.patch
lock-validator-core-early_boot_irqs_-build-fix-sparc64-sparc-m68k-alpha-cris-irqtrace-build-fix.patch
lock-validator-core-fix-compiler-warning.patch
lock-validator-core-add-config_debug_non_nested_unlocks.patch
lock-validator-procfs.patch
lock-validator-core-multichar-fix.patch
lock-validator-core-count_matching_names-fix.patch
lock-validator-design-docs.patch
lock-validator-prove-rwsem-locking-correctness.patch
lock-validator-prove-rwsem-locking-correctness-fix.patch
lock-validator-prove-rwsem-locking-correctness-powerpc-fix.patch
lock-validator-prove-spinlock-rwlock-locking-correctness.patch
lock-validator-prove-mutex-locking-correctness.patch
lock-validator-prove-mutex-locking-correctness-fix-null-type-name-bug.patch
better-lock-debugging-remove-mutex-deadlock-checking-code.patch
lock-validator-print-all-lock-types-on-sysrq-d.patch
lock-validator-x86_64-early-init.patch
lock-validator-smp-alternatives-workaround.patch
lock-validator-do-not-recurse-in-printk.patch
lock-validator-disable-nmi-watchdog-if-config_lockdep.patch
lock-validator-disable-nmi-watchdog-if-config_lockdep-i386.patch
lock-validator-disable-nmi-watchdog-if-config_lockdep-x86_64.patch
lock-validator-special-locking-bdev.patch
lock-validator-special-locking-bdev-fix.patch
lock-validator-special-locking-direct-io.patch
lock-validator-special-locking-serial.patch
lock-validator-special-locking-serial-fix.patch
lock-validator-special-locking-dcache.patch
lock-validator-special-locking-i_mutex.patch
lock-validator-special-locking-s_lock.patch
lock-validator-special-locking-futex.patch
lock-validator-special-locking-genirq.patch
lock-validator-special-locking-genirq-lock-validator-early_init_irq_lock_type-build-fix.patch
lock-validator-special-locking-completions.patch
lock-validator-special-locking-waitqueues.patch
lock-validator-special-locking-mm.patch
lock-validator-special-locking-serio.patch
lock-validator-special-locking-slab.patch
lock-validator-special-locking-skb_queue_head_init.patch
lock-validator-special-locking-net-ipv4-igmpcpatch.patch
lock-validator-special-locking-net-ipv4-igmpc-2.patch
lock-validator-special-locking-timerc.patch
lock-validator-special-locking-schedc.patch
lock-validator-special-locking-sctp.patch
lock-validator-special-locking-hrtimerc.patch
lock-validator-special-locking-sock_lock_init.patch
lock-validator-special-locking-af_unix.patch
lock-validator-special-locking-bh_lock_sock.patch
lock-validator-special-locking-mmap_sem.patch
lock-validator-special-locking-sb-s_umount.patch
lock-validator-special-locking-reiser4-false-positive.patch
lock-validator-special-locking-sb-s_umount-fix.patch
lock-validator-special-locking-sb-s_umount-2.patch
lock-validator-special-locking-sb-s_umount-2-fix.patch
lockdep-annotate-rpc_populate-for.patch
lock-validator-special-locking-jbd.patch
lock-validator-special-locking-posix-timers.patch
lock-validator-special-locking-sch_genericc.patch
lock-validator-special-locking-xfrm.patch
lockdep-add-i_mutex-ordering-annotations-to-the-sunrpc.patch
lockdep-add-parent-child-annotations-to-usbfs.patch
lock-validator-special-locking-sound-core-seq-seq_portsc.patch
lock-validator-special-locking-sound-core-seq-seq_devicec.patch
lock-validator-special-locking-sound-core-seq-seq_devicec-fix.patch
lock-validator-fix-rt_hash_lock_sz.patch
lock-validator-introduce-irq__lockdep.patch
locking-validator-special-rule-8390c-disable_irq.patch
locking-validator-special-rule-3c59xc-disable_irq.patch
lock-validator-enable-lock-validator-in-kconfig.patch
lock-validator-enable-lock-validator-in-kconfig-require-trace_irqflags_support.patch
lock-validator-enable-lock-validator-in-kconfig-not-yet.patch
lock-validator-enable-lock-validator-in-kconfig-add-config_debug_non_nested_unlocks-kconfig.patch
lockdep-one-stacktrace-column-if-config_lockdep=y.patch
i386-remove-multi-entry-backtraces.patch
lockdep-further-improve-stacktrace-output.patch
lock-validator-irqtrace-support-non-x86-architectures.patch
lock-validator-disable-oprofile-if-lockdep=y.patch
lock-validator-select-kallsyms_all.patch
lock-validator-special-locking-kgdb.patch
detect-atomic-counter-underflows.patch
debug-shared-irqs.patch
make-frame_pointer-default=y.patch
mutex-subsystem-synchro-test-module.patch
vdso-print-fatal-signals.patch
vdso-improve-print_fatal_signals-support-by-adding-memory-maps.patch
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