Dear RT Folks, I'm pleased to announce the 3.4.13-rt22 stable release.
You can get this release via the git tree at: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git Head SHA1: be16a1145ed848b4e96e70cba6e0f8e4a68a255d Or to build 3.4.13-rt22 directly, the following patches should be applied: http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.4.tar.xz http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.4.13.xz http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/patch-3.4.13-rt22.patch.xz You can also build from 3.4.13-rt21 by applying the incremental patch: http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/incr/patch-3.4.13-rt21-rt22.patch.xz Enjoy, -- Steve Changes from 3.4.13-rt21: --- Steven Rostedt (2): softirq: Init softirq local lock after per cpu section is set up Linux 3.4.13-rt22 Thomas Gleixner (6): random: Make it work on rt mm: slab: Fix potential deadlock mm: page_alloc: Use local_lock_on() instead of plain spinlock rt: rwsem/rwlock: lockdep annotations sched: Better debug output for might sleep stomp_machine: Use mutex_trylock when called from inactive cpu ---- drivers/char/random.c | 10 ++++++---- include/linux/irqdesc.h | 1 + include/linux/locallock.h | 19 +++++++++++++++++++ include/linux/random.h | 2 +- include/linux/sched.h | 4 ++++ init/main.c | 2 +- kernel/irq/handle.c | 7 +++++-- kernel/irq/manage.c | 6 ++++++ kernel/rt.c | 46 ++++++++++++++++++++++++--------------------- kernel/sched/core.c | 23 +++++++++++++++++++++-- kernel/stop_machine.c | 13 +++++++++---- localversion-rt | 2 +- mm/page_alloc.c | 4 ++-- mm/slab.c | 10 ++-------- 14 files changed, 103 insertions(+), 46 deletions(-) --------------------------- diff --git a/drivers/char/random.c b/drivers/char/random.c index feae549..f786798 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -745,18 +745,16 @@ EXPORT_SYMBOL_GPL(add_input_randomness); static DEFINE_PER_CPU(struct fast_pool, irq_randomness); -void add_interrupt_randomness(int irq, int irq_flags) +void add_interrupt_randomness(int irq, int irq_flags, __u64 ip) { struct entropy_store *r; struct fast_pool *fast_pool = &__get_cpu_var(irq_randomness); - struct pt_regs *regs = get_irq_regs(); unsigned long now = jiffies; __u32 input[4], cycles = get_cycles(); input[0] = cycles ^ jiffies; input[1] = irq; - if (regs) { - __u64 ip = instruction_pointer(regs); + if (ip) { input[2] = ip; input[3] = ip >> 32; } @@ -770,7 +768,11 @@ void add_interrupt_randomness(int irq, int irq_flags) fast_pool->last = now; r = nonblocking_pool.initialized ? &input_pool : &nonblocking_pool; +#ifndef CONFIG_PREEMPT_RT_FULL __mix_pool_bytes(r, &fast_pool->pool, sizeof(fast_pool->pool), NULL); +#else + mix_pool_bytes(r, &fast_pool->pool, sizeof(fast_pool->pool), NULL); +#endif /* * If we don't have a valid cycle counter, and we see * back-to-back timer interrupts, then skip giving credit for diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index 9a323d1..5bf5add 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -52,6 +52,7 @@ struct irq_desc { unsigned int irq_count; /* For detecting broken IRQs */ unsigned long last_unhandled; /* Aging timer for unhandled count */ unsigned int irqs_unhandled; + u64 random_ip; raw_spinlock_t lock; struct cpumask *percpu_enabled; #ifdef CONFIG_SMP diff --git a/include/linux/locallock.h b/include/linux/locallock.h index 8fbc393..f1804a3 100644 --- a/include/linux/locallock.h +++ b/include/linux/locallock.h @@ -96,6 +96,9 @@ static inline void __local_lock_irq(struct local_irq_lock *lv) #define local_lock_irq(lvar) \ do { __local_lock_irq(&get_local_var(lvar)); } while (0) +#define local_lock_irq_on(lvar, cpu) \ + do { __local_lock_irq(&per_cpu(lvar, cpu)); } while (0) + static inline void __local_unlock_irq(struct local_irq_lock *lv) { LL_WARN(!lv->nestcnt); @@ -111,6 +114,11 @@ static inline void __local_unlock_irq(struct local_irq_lock *lv) put_local_var(lvar); \ } while (0) +#define local_unlock_irq_on(lvar, cpu) \ + do { \ + __local_unlock_irq(&per_cpu(lvar, cpu)); \ + } while (0) + static inline int __local_lock_irqsave(struct local_irq_lock *lv) { if (lv->owner != current) { @@ -129,6 +137,12 @@ static inline int __local_lock_irqsave(struct local_irq_lock *lv) _flags = __get_cpu_var(lvar).flags; \ } while (0) +#define local_lock_irqsave_on(lvar, _flags, cpu) \ + do { \ + __local_lock_irqsave(&per_cpu(lvar, cpu)); \ + _flags = per_cpu(lvar, cpu).flags; \ + } while (0) + static inline int __local_unlock_irqrestore(struct local_irq_lock *lv, unsigned long flags) { @@ -148,6 +162,11 @@ static inline int __local_unlock_irqrestore(struct local_irq_lock *lv, put_local_var(lvar); \ } while (0) +#define local_unlock_irqrestore_on(lvar, flags, cpu) \ + do { \ + __local_unlock_irqrestore(&per_cpu(lvar, cpu), flags); \ + } while (0) + #define local_spin_trylock_irq(lvar, lock) \ ({ \ int __locked; \ diff --git a/include/linux/random.h b/include/linux/random.h index ac621ce..9ae01e2 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -51,7 +51,7 @@ struct rnd_state { extern void add_device_randomness(const void *, unsigned int); extern void add_input_randomness(unsigned int type, unsigned int code, unsigned int value); -extern void add_interrupt_randomness(int irq, int irq_flags); +extern void add_interrupt_randomness(int irq, int irq_flags, __u64 ip); extern void get_random_bytes(void *buf, int nbytes); extern void get_random_bytes_arch(void *buf, int nbytes); diff --git a/include/linux/sched.h b/include/linux/sched.h index 6f342d8..f291347 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1655,6 +1655,10 @@ struct task_struct { int kmap_idx; pte_t kmap_pte[KM_TYPE_NR]; #endif + +#ifdef CONFIG_DEBUG_PREEMPT + unsigned long preempt_disable_ip; +#endif }; #ifdef CONFIG_PREEMPT_RT_FULL diff --git a/init/main.c b/init/main.c index f07f2b0..cee1a91 100644 --- a/init/main.c +++ b/init/main.c @@ -490,7 +490,6 @@ asmlinkage void __init start_kernel(void) * Interrupts are still disabled. Do necessary setups, then * enable them */ - softirq_early_init(); tick_init(); boot_cpu_init(); page_address_init(); @@ -501,6 +500,7 @@ asmlinkage void __init start_kernel(void) setup_command_line(command_line); setup_nr_cpu_ids(); setup_per_cpu_areas(); + softirq_early_init(); smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ build_all_zonelists(NULL); diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 311c4e6..7f50c55 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -132,6 +132,8 @@ static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action) irqreturn_t handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action) { + struct pt_regs *regs = get_irq_regs(); + u64 ip = regs ? instruction_pointer(regs) : 0; irqreturn_t retval = IRQ_NONE; unsigned int flags = 0, irq = desc->irq_data.irq; @@ -173,8 +175,9 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action) } while (action); #ifndef CONFIG_PREEMPT_RT_FULL - /* FIXME: Can we unbreak that ? */ - add_interrupt_randomness(irq, flags); + add_interrupt_randomness(irq, flags, ip); +#else + desc->random_ip = ip; #endif if (!noirqdebug) diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index ede56ac..90bf44a 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -814,6 +814,12 @@ static int irq_thread(void *data) if (!noirqdebug) note_interrupt(action->irq, desc, action_ret); +#ifdef CONFIG_PREEMPT_RT_FULL + migrate_disable(); + add_interrupt_randomness(action->irq, 0, + desc->random_ip ^ (u64) action); + migrate_enable(); +#endif wake_threads_waitq(desc); } diff --git a/kernel/rt.c b/kernel/rt.c index 092d6b3..aa10504 100644 --- a/kernel/rt.c +++ b/kernel/rt.c @@ -216,15 +216,17 @@ int __lockfunc rt_read_trylock(rwlock_t *rwlock) * write locked. */ migrate_disable(); - if (rt_mutex_owner(lock) != current) + if (rt_mutex_owner(lock) != current) { ret = rt_mutex_trylock(lock); - else if (!rwlock->read_depth) + if (ret) + rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_); + } else if (!rwlock->read_depth) { ret = 0; + } - if (ret) { + if (ret) rwlock->read_depth++; - rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_); - } else + else migrate_enable(); return ret; @@ -242,13 +244,13 @@ void __lockfunc rt_read_lock(rwlock_t *rwlock) { struct rt_mutex *lock = &rwlock->lock; - rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_); - /* * recursive read locks succeed when current owns the lock */ - if (rt_mutex_owner(lock) != current) + if (rt_mutex_owner(lock) != current) { + rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_); __rt_spin_lock(lock); + } rwlock->read_depth++; } @@ -264,11 +266,11 @@ EXPORT_SYMBOL(rt_write_unlock); void __lockfunc rt_read_unlock(rwlock_t *rwlock) { - rwlock_release(&rwlock->dep_map, 1, _RET_IP_); - /* Release the lock only when read_depth is down to 0 */ - if (--rwlock->read_depth == 0) + if (--rwlock->read_depth == 0) { + rwlock_release(&rwlock->dep_map, 1, _RET_IP_); __rt_spin_unlock(&rwlock->lock); + } } EXPORT_SYMBOL(rt_read_unlock); @@ -315,9 +317,10 @@ EXPORT_SYMBOL(rt_up_write); void rt_up_read(struct rw_semaphore *rwsem) { - rwsem_release(&rwsem->dep_map, 1, _RET_IP_); - if (--rwsem->read_depth == 0) + if (--rwsem->read_depth == 0) { + rwsem_release(&rwsem->dep_map, 1, _RET_IP_); rt_mutex_unlock(&rwsem->lock); + } } EXPORT_SYMBOL(rt_up_read); @@ -366,15 +369,16 @@ int rt_down_read_trylock(struct rw_semaphore *rwsem) * but not when read_depth == 0 which means that the rwsem is * write locked. */ - if (rt_mutex_owner(lock) != current) + if (rt_mutex_owner(lock) != current) { ret = rt_mutex_trylock(&rwsem->lock); - else if (!rwsem->read_depth) + if (ret) + rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_); + } else if (!rwsem->read_depth) { ret = 0; + } - if (ret) { + if (ret) rwsem->read_depth++; - rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_); - } return ret; } EXPORT_SYMBOL(rt_down_read_trylock); @@ -383,10 +387,10 @@ static void __rt_down_read(struct rw_semaphore *rwsem, int subclass) { struct rt_mutex *lock = &rwsem->lock; - rwsem_acquire_read(&rwsem->dep_map, subclass, 0, _RET_IP_); - - if (rt_mutex_owner(lock) != current) + if (rt_mutex_owner(lock) != current) { + rwsem_acquire(&rwsem->dep_map, subclass, 0, _RET_IP_); rt_mutex_lock(&rwsem->lock); + } rwsem->read_depth++; } diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 66d4dea..263fd96 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3215,8 +3215,13 @@ void __kprobes add_preempt_count(int val) DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= PREEMPT_MASK - 10); #endif - if (preempt_count() == val) - trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); + if (preempt_count() == val) { + unsigned long ip = get_parent_ip(CALLER_ADDR1); +#ifdef CONFIG_DEBUG_PREEMPT + current->preempt_disable_ip = ip; +#endif + trace_preempt_off(CALLER_ADDR0, ip); + } } EXPORT_SYMBOL(add_preempt_count); @@ -3259,6 +3264,13 @@ static noinline void __schedule_bug(struct task_struct *prev) print_modules(); if (irqs_disabled()) print_irqtrace_events(prev); +#ifdef DEBUG_PREEMPT + if (in_atomic_preempt_off()) { + pr_err("Preemption disabled at:"); + print_ip_sym(current->preempt_disable_ip); + pr_cont("\n"); + } +#endif dump_stack(); } @@ -7479,6 +7491,13 @@ void __might_sleep(const char *file, int line, int preempt_offset) debug_show_held_locks(current); if (irqs_disabled()) print_irqtrace_events(current); +#ifdef DEBUG_PREEMPT + if (!preempt_count_equals(preempt_offset)) { + pr_err("Preemption disabled at:"); + print_ip_sym(current->preempt_disable_ip); + pr_cont("\n"); + } +#endif dump_stack(); } EXPORT_SYMBOL(__might_sleep); diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 561ba3a..e98c70b 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -158,7 +158,7 @@ static DEFINE_PER_CPU(struct cpu_stop_work, stop_cpus_work); static void queue_stop_cpus_work(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg, - struct cpu_stop_done *done) + struct cpu_stop_done *done, bool inactive) { struct cpu_stop_work *work; unsigned int cpu; @@ -175,7 +175,12 @@ static void queue_stop_cpus_work(const struct cpumask *cpumask, * Make sure that all work is queued on all cpus before we * any of the cpus can execute it. */ - mutex_lock(&stopper_lock); + if (!inactive) { + mutex_lock(&stopper_lock); + } else { + while (!mutex_trylock(&stopper_lock)) + cpu_relax(); + } for_each_cpu(cpu, cpumask) cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), &per_cpu(stop_cpus_work, cpu)); @@ -188,7 +193,7 @@ static int __stop_cpus(const struct cpumask *cpumask, struct cpu_stop_done done; cpu_stop_init_done(&done, cpumask_weight(cpumask)); - queue_stop_cpus_work(cpumask, fn, arg, &done); + queue_stop_cpus_work(cpumask, fn, arg, &done, false); wait_for_stop_done(&done); return done.executed ? done.ret : -ENOENT; } @@ -601,7 +606,7 @@ int stop_machine_from_inactive_cpu(int (*fn)(void *), void *data, set_state(&smdata, STOPMACHINE_PREPARE); cpu_stop_init_done(&done, num_active_cpus()); queue_stop_cpus_work(cpu_active_mask, stop_machine_cpu_stop, &smdata, - &done); + &done, true); ret = stop_machine_cpu_stop(&smdata); /* Busy wait for completion. */ diff --git a/localversion-rt b/localversion-rt index 6c6cde1..c29508d 100644 --- a/localversion-rt +++ b/localversion-rt @@ -1 +1 @@ --rt21 +-rt22 diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e097a56..9be717b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -221,9 +221,9 @@ static DEFINE_LOCAL_IRQ_LOCK(pa_lock); #ifdef CONFIG_PREEMPT_RT_BASE # define cpu_lock_irqsave(cpu, flags) \ - spin_lock_irqsave(&per_cpu(pa_lock, cpu).lock, flags) + local_lock_irqsave_on(pa_lock, flags, cpu) # define cpu_unlock_irqrestore(cpu, flags) \ - spin_unlock_irqrestore(&per_cpu(pa_lock, cpu).lock, flags) + local_unlock_irqrestore_on(pa_lock, flags, cpu) #else # define cpu_lock_irqsave(cpu, flags) local_irq_save(flags) # define cpu_unlock_irqrestore(cpu, flags) local_irq_restore(flags) diff --git a/mm/slab.c b/mm/slab.c index 64eb636..09addf6 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -751,18 +751,12 @@ slab_on_each_cpu(void (*func)(void *arg, int this_cpu), void *arg) static void lock_slab_on(unsigned int cpu) { - if (cpu == smp_processor_id()) - local_lock_irq(slab_lock); - else - local_spin_lock_irq(slab_lock, &per_cpu(slab_lock, cpu).lock); + local_lock_irq_on(slab_lock, cpu); } static void unlock_slab_on(unsigned int cpu) { - if (cpu == smp_processor_id()) - local_unlock_irq(slab_lock); - else - local_spin_unlock_irq(slab_lock, &per_cpu(slab_lock, cpu).lock); + local_unlock_irq_on(slab_lock, cpu); } #endif -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
