diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/ftrace.c | 44 | ||||
| -rw-r--r-- | kernel/trace/ring_buffer.c | 248 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 453 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 4 | ||||
| -rw-r--r-- | kernel/trace/trace_printk.c | 4 |
5 files changed, 453 insertions, 300 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 0fa92f677c92..cf81f27ce6c6 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2469,57 +2469,35 @@ static int ftrace_avail_open(struct inode *inode, struct file *file) { struct ftrace_iterator *iter; - int ret; if (unlikely(ftrace_disabled)) return -ENODEV; - iter = kzalloc(sizeof(*iter), GFP_KERNEL); - if (!iter) - return -ENOMEM; - - iter->pg = ftrace_pages_start; - iter->ops = &global_ops; - - ret = seq_open(file, &show_ftrace_seq_ops); - if (!ret) { - struct seq_file *m = file->private_data; - - m->private = iter; - } else { - kfree(iter); + iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); + if (iter) { + iter->pg = ftrace_pages_start; + iter->ops = &global_ops; } - return ret; + return iter ? 0 : -ENOMEM; } static int ftrace_enabled_open(struct inode *inode, struct file *file) { struct ftrace_iterator *iter; - int ret; if (unlikely(ftrace_disabled)) return -ENODEV; - iter = kzalloc(sizeof(*iter), GFP_KERNEL); - if (!iter) - return -ENOMEM; - - iter->pg = ftrace_pages_start; - iter->flags = FTRACE_ITER_ENABLED; - iter->ops = &global_ops; - - ret = seq_open(file, &show_ftrace_seq_ops); - if (!ret) { - struct seq_file *m = file->private_data; - - m->private = iter; - } else { - kfree(iter); + iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); + if (iter) { + iter->pg = ftrace_pages_start; + iter->flags = FTRACE_ITER_ENABLED; + iter->ops = &global_ops; } - return ret; + return iter ? 0 : -ENOMEM; } static void ftrace_filter_reset(struct ftrace_hash *hash) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index cf8d11e91efd..2d5eb3320827 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -449,6 +449,7 @@ struct ring_buffer_per_cpu { raw_spinlock_t reader_lock; /* serialize readers */ arch_spinlock_t lock; struct lock_class_key lock_key; + unsigned int nr_pages; struct list_head *pages; struct buffer_page *head_page; /* read from head */ struct buffer_page *tail_page; /* write to tail */ @@ -466,10 +467,12 @@ struct ring_buffer_per_cpu { unsigned long read_bytes; u64 write_stamp; u64 read_stamp; + /* ring buffer pages to update, > 0 to add, < 0 to remove */ + int nr_pages_to_update; + struct list_head new_pages; /* new pages to add */ }; struct ring_buffer { - unsigned pages; unsigned flags; int cpus; atomic_t record_disabled; @@ -963,14 +966,10 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer) return 0; } -static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, - unsigned nr_pages) +static int __rb_allocate_pages(int nr_pages, struct list_head *pages, int cpu) { + int i; struct buffer_page *bpage, *tmp; - LIST_HEAD(pages); - unsigned i; - - WARN_ON(!nr_pages); for (i = 0; i < nr_pages; i++) { struct page *page; @@ -981,15 +980,13 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, */ bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()), GFP_KERNEL | __GFP_NORETRY, - cpu_to_node(cpu_buffer->cpu)); + cpu_to_node(cpu)); if (!bpage) goto free_pages; - rb_check_bpage(cpu_buffer, bpage); + list_add(&bpage->list, pages); - list_add(&bpage->list, &pages); - - page = alloc_pages_node(cpu_to_node(cpu_buffer->cpu), + page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL | __GFP_NORETRY, 0); if (!page) goto free_pages; @@ -997,6 +994,27 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, rb_init_page(bpage->page); } + return 0; + +free_pages: + list_for_each_entry_safe(bpage, tmp, pages, list) { + list_del_init(&bpage->list); + free_buffer_page(bpage); + } + + return -ENOMEM; +} + +static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, + unsigned nr_pages) +{ + LIST_HEAD(pages); + + WARN_ON(!nr_pages); + + if (__rb_allocate_pages(nr_pages, &pages, cpu_buffer->cpu)) + return -ENOMEM; + /* * The ring buffer page list is a circular list that does not * start and end with a list head. All page list items point to @@ -1005,20 +1023,15 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, cpu_buffer->pages = pages.next; list_del(&pages); + cpu_buffer->nr_pages = nr_pages; + rb_check_pages(cpu_buffer); return 0; - - free_pages: - list_for_each_entry_safe(bpage, tmp, &pages, list) { - list_del_init(&bpage->list); - free_buffer_page(bpage); - } - return -ENOMEM; } static struct ring_buffer_per_cpu * -rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) +rb_allocate_cpu_buffer(struct ring_buffer *buffer, int nr_pages, int cpu) { struct ring_buffer_per_cpu *cpu_buffer; struct buffer_page *bpage; @@ -1052,7 +1065,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) INIT_LIST_HEAD(&cpu_buffer->reader_page->list); - ret = rb_allocate_pages(cpu_buffer, buffer->pages); + ret = rb_allocate_pages(cpu_buffer, nr_pages); if (ret < 0) goto fail_free_reader; @@ -1113,7 +1126,7 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags, { struct ring_buffer *buffer; int bsize; - int cpu; + int cpu, nr_pages; /* keep it in its own cache line */ buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()), @@ -1124,14 +1137,14 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags, if (!alloc_cpumask_var(&buffer->cpumask, GFP_KERNEL)) goto fail_free_buffer; - buffer->pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE); + nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE); buffer->flags = flags; buffer->clock = trace_clock_local; buffer->reader_lock_key = key; /* need at least two pages */ - if (buffer->pages < 2) - buffer->pages = 2; + if (nr_pages < 2) + nr_pages = 2; /* * In case of non-hotplug cpu, if the ring-buffer is allocated @@ -1154,7 +1167,7 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags, for_each_buffer_cpu(buffer, cpu) { buffer->buffers[cpu] = - rb_allocate_cpu_buffer(buffer, cpu); + rb_allocate_cpu_buffer(buffer, nr_pages, cpu); if (!buffer->buffers[cpu]) goto fail_free_buffers; } @@ -1276,6 +1289,18 @@ out: raw_spin_unlock_irq(&cpu_buffer->reader_lock); } +static void update_pages_handler(struct ring_buffer_per_cpu *cpu_buffer) +{ + if (cpu_buffer->nr_pages_to_update > 0) + rb_insert_pages(cpu_buffer, &cpu_buffer->new_pages, + cpu_buffer->nr_pages_to_update); + else + rb_remove_pages(cpu_buffer, -cpu_buffer->nr_pages_to_update); + cpu_buffer->nr_pages += cpu_buffer->nr_pages_to_update; + /* reset this value */ + cpu_buffer->nr_pages_to_update = 0; +} + /** * ring_buffer_resize - resize the ring buffer * @buffer: the buffer to resize. @@ -1285,14 +1310,12 @@ out: * * Returns -1 on failure. */ -int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) +int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, + int cpu_id) { struct ring_buffer_per_cpu *cpu_buffer; - unsigned nr_pages, rm_pages, new_pages; - struct buffer_page *bpage, *tmp; - unsigned long buffer_size; - LIST_HEAD(pages); - int i, cpu; + unsigned nr_pages; + int cpu; /* * Always succeed at resizing a non-existent buffer: @@ -1302,15 +1325,11 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) size = DIV_ROUND_UP(size, BUF_PAGE_SIZE); size *= BUF_PAGE_SIZE; - buffer_size = buffer->pages * BUF_PAGE_SIZE; /* we need a minimum of two pages */ if (size < BUF_PAGE_SIZE * 2) size = BUF_PAGE_SIZE * 2; - if (size == buffer_size) - return size; - atomic_inc(&buffer->record_disabled); /* Make sure all writers are done with this buffer. */ @@ -1321,68 +1340,56 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE); - if (size < buffer_size) { - - /* easy case, just free pages */ - if (RB_WARN_ON(buffer, nr_pages >= buffer->pages)) - goto out_fail; - - rm_pages = buffer->pages - nr_pages; - + if (cpu_id == RING_BUFFER_ALL_CPUS) { + /* calculate the pages to update */ for_each_buffer_cpu(buffer, cpu) { cpu_buffer = buffer->buffers[cpu]; - rb_remove_pages(cpu_buffer, rm_pages); - } - goto out; - } - /* - * This is a bit more difficult. We only want to add pages - * when we can allocate enough for all CPUs. We do this - * by allocating all the pages and storing them on a local - * link list. If we succeed in our allocation, then we - * add these pages to the cpu_buffers. Otherwise we just free - * them all and return -ENOMEM; - */ - if (RB_WARN_ON(buffer, nr_pages <= buffer->pages)) - goto out_fail; + cpu_buffer->nr_pages_to_update = nr_pages - + cpu_buffer->nr_pages; - new_pages = nr_pages - buffer->pages; + /* + * nothing more to do for removing pages or no update + */ + if (cpu_buffer->nr_pages_to_update <= 0) + continue; - for_each_buffer_cpu(buffer, cpu) { - for (i = 0; i < new_pages; i++) { - struct page *page; /* - * __GFP_NORETRY flag makes sure that the allocation - * fails gracefully without invoking oom-killer and - * the system is not destabilized. + * to add pages, make sure all new pages can be + * allocated without receiving ENOMEM */ - bpage = kzalloc_node(ALIGN(sizeof(*bpage), - cache_line_size()), - GFP_KERNEL | __GFP_NORETRY, - cpu_to_node(cpu)); - if (!bpage) - goto free_pages; - list_add(&bpage->list, &pages); - page = alloc_pages_node(cpu_to_node(cpu), - GFP_KERNEL | __GFP_NORETRY, 0); - if (!page) - goto free_pages; - bpage->page = page_address(page); - rb_init_page(bpage->page); + INIT_LIST_HEAD(&cpu_buffer->new_pages); + if (__rb_allocate_pages(cpu_buffer->nr_pages_to_update, + &cpu_buffer->new_pages, cpu)) + /* not enough memory for new pages */ + goto no_mem; } - } - for_each_buffer_cpu(buffer, cpu) { - cpu_buffer = buffer->buffers[cpu]; - rb_insert_pages(cpu_buffer, &pages, new_pages); - } + /* wait for all the updates to complete */ + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + if (cpu_buffer->nr_pages_to_update) { + update_pages_handler(cpu_buffer); + } + } + } else { + cpu_buffer = buffer->buffers[cpu_id]; + if (nr_pages == cpu_buffer->nr_pages) + goto out; - if (RB_WARN_ON(buffer, !list_empty(&pages))) - goto out_fail; + cpu_buffer->nr_pages_to_update = nr_pages - + cpu_buffer->nr_pages; + + INIT_LIST_HEAD(&cpu_buffer->new_pages); + if (cpu_buffer->nr_pages_to_update > 0 && + __rb_allocate_pages(cpu_buffer->nr_pages_to_update, + &cpu_buffer->new_pages, cpu_id)) + goto no_mem; + + update_pages_handler(cpu_buffer); + } out: - buffer->pages = nr_pages; put_online_cpus(); mutex_unlock(&buffer->mutex); @@ -1390,25 +1397,24 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) return size; - free_pages: - list_for_each_entry_safe(bpage, tmp, &pages, list) { - list_del_init(&bpage->list); - free_buffer_page(bpage); + no_mem: + for_each_buffer_cpu(buffer, cpu) { + struct buffer_page *bpage, *tmp; + cpu_buffer = buffer->buffers[cpu]; + /* reset this number regardless */ + cpu_buffer->nr_pages_to_update = 0; + if (list_empty(&cpu_buffer->new_pages)) + continue; + list_for_each_entry_safe(bpage, tmp, &cpu_buffer->new_pages, + list) { + list_del_init(&bpage->list); + free_buffer_page(bpage); + } } put_online_cpus(); mutex_unlock(&buffer->mutex); atomic_dec(&buffer->record_disabled); return -ENOMEM; - - /* - * Something went totally wrong, and we are too paranoid - * to even clean up the mess. - */ - out_fail: - put_online_cpus(); - mutex_unlock(&buffer->mutex); - atomic_dec(&buffer->record_disabled); - return -1; } EXPORT_SYMBOL_GPL(ring_buffer_resize); @@ -1510,7 +1516,7 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer) * assign the commit to the tail. */ again: - max_count = cpu_buffer->buffer->pages * 100; + max_count = cpu_buffer->nr_pages * 100; while (cpu_buffer->commit_page != cpu_buffer->tail_page) { if (RB_WARN_ON(cpu_buffer, !(--max_count))) @@ -3588,9 +3594,18 @@ EXPORT_SYMBOL_GPL(ring_buffer_read); * ring_buffer_size - return the size of the ring buffer (in bytes) * @buffer: The ring buffer. */ -unsigned long ring_buffer_size(struct ring_buffer *buffer) +unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu) { - return BUF_PAGE_SIZE * buffer->pages; + /* + * Earlier, this method returned + * BUF_PAGE_SIZE * buffer->nr_pages + * Since the nr_pages field is now removed, we have converted this to + * return the per cpu buffer value. + */ + if (!cpumask_test_cpu(cpu, buffer->cpumask)) + return 0; + + return BUF_PAGE_SIZE * buffer->buffers[cpu]->nr_pages; } EXPORT_SYMBOL_GPL(ring_buffer_size); @@ -3765,8 +3780,11 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, !cpumask_test_cpu(cpu, buffer_b->cpumask)) goto out; + cpu_buffer_a = buffer_a->buffers[cpu]; + cpu_buffer_b = buffer_b->buffers[cpu]; + /* At least make sure the two buffers are somewhat the same */ - if (buffer_a->pages != buffer_b->pages) + if (cpu_buffer_a->nr_pages != cpu_buffer_b->nr_pages) goto out; ret = -EAGAIN; @@ -3780,9 +3798,6 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, if (atomic_read(&buffer_b->record_disabled)) goto out; - cpu_buffer_a = buffer_a->buffers[cpu]; - cpu_buffer_b = buffer_b->buffers[cpu]; - if (atomic_read(&cpu_buffer_a->record_disabled)) goto out; @@ -4071,6 +4086,8 @@ static int rb_cpu_notify(struct notifier_block *self, struct ring_buffer *buffer = container_of(self, struct ring_buffer, cpu_notify); long cpu = (long)hcpu; + int cpu_i, nr_pages_same; + unsigned int nr_pages; switch (action) { case CPU_UP_PREPARE: @@ -4078,8 +4095,23 @@ static int rb_cpu_notify(struct notifier_block *self, if (cpumask_test_cpu(cpu, buffer->cpumask)) return NOTIFY_OK; + nr_pages = 0; + nr_pages_same = 1; + /* check if all cpu sizes are same */ + for_each_buffer_cpu(buffer, cpu_i) { + /* fill in the size from first enabled cpu */ + if (nr_pages == 0) + nr_pages = buffer->buffers[cpu_i]->nr_pages; + if (nr_pages != buffer->buffers[cpu_i]->nr_pages) { + nr_pages_same = 0; + break; + } + } + /* allocate minimum pages, user can later expand it */ + if (!nr_pages_same) + nr_pages = 2; buffer->buffers[cpu] = - rb_allocate_cpu_buffer(buffer, cpu); + rb_allocate_cpu_buffer(buffer, nr_pages, cpu); if (!buffer->buffers[cpu]) { WARN(1, "failed to allocate ring buffer on CPU %ld\n", cpu); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ed7b5d1e12f4..48ef4960ec90 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -87,18 +87,6 @@ static int tracing_disabled = 1; DEFINE_PER_CPU(int, ftrace_cpu_disabled); -static inline void ftrace_disable_cpu(void) -{ - preempt_disable(); - __this_cpu_inc(ftrace_cpu_disabled); -} - -static inline void ftrace_enable_cpu(void) -{ - __this_cpu_dec(ftrace_cpu_disabled); - preempt_enable(); -} - cpumask_var_t __read_mostly tracing_buffer_mask; /* @@ -629,7 +617,6 @@ ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt) static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) { int len; - void *ret; if (s->len <= s->readpos) return -EBUSY; @@ -637,9 +624,7 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) len = s->len - s->readpos; if (cnt > len) cnt = len; - ret = memcpy(buf, s->buffer + s->readpos, cnt); - if (!ret) - return -EFAULT; + memcpy(buf, s->buffer + s->readpos, cnt); s->readpos += cnt; return cnt; @@ -751,8 +736,6 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) arch_spin_lock(&ftrace_max_lock); - ftrace_disable_cpu(); - ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu); if (ret == -EBUSY) { @@ -766,8 +749,6 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) "Failed to swap buffers due to commit in progress\n"); } - ftrace_enable_cpu(); - WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); __update_max_tr(tr, tsk, cpu); @@ -841,7 +822,8 @@ __acquires(kernel_lock) /* If we expanded the buffers, make sure the max is expanded too */ if (ring_buffer_expanded && type->use_max_tr) - ring_buffer_resize(max_tr.buffer, trace_buf_size); + ring_buffer_resize(max_tr.buffer, trace_buf_size, + RING_BUFFER_ALL_CPUS); /* the test is responsible for initializing and enabling */ pr_info("Testing tracer %s: ", type->name); @@ -857,7 +839,8 @@ __acquires(kernel_lock) /* Shrink the max buffer again */ if (ring_buffer_expanded && type->use_max_tr) - ring_buffer_resize(max_tr.buffer, 1); + ring_buffer_resize(max_tr.buffer, 1, + RING_BUFFER_ALL_CPUS); printk(KERN_CONT "PASSED\n"); } @@ -917,13 +900,6 @@ out: mutex_unlock(&trace_types_lock); } -static void __tracing_reset(struct ring_buffer *buffer, int cpu) -{ - ftrace_disable_cpu(); - ring_buffer_reset_cpu(buffer, cpu); - ftrace_enable_cpu(); -} - void tracing_reset(struct trace_array *tr, int cpu) { struct ring_buffer *buffer = tr->buffer; @@ -932,7 +908,7 @@ void tracing_reset(struct trace_array *tr, int cpu) /* Make sure all commits have finished */ synchronize_sched(); - __tracing_reset(buffer, cpu); + ring_buffer_reset_cpu(buffer, cpu); ring_buffer_record_enable(buffer); } @@ -950,7 +926,7 @@ void tracing_reset_online_cpus(struct trace_array *tr) tr->time_start = ftrace_now(tr->cpu); for_each_online_cpu(cpu) - __tracing_reset(buffer, cpu); + ring_buffer_reset_cpu(buffer, cpu); ring_buffer_record_enable(buffer); } @@ -1498,25 +1474,119 @@ static void __trace_userstack(struct trace_array *tr, unsigned long flags) #endif /* CONFIG_STACKTRACE */ +/* created for use with alloc_percpu */ +struct trace_buffer_struct { + char buffer[TRACE_BUF_SIZE]; +}; + +static struct trace_buffer_struct *trace_percpu_buffer; +static struct trace_buffer_struct *trace_percpu_sirq_buffer; +static struct trace_buffer_struct *trace_percpu_irq_buffer; +static struct trace_buffer_struct *trace_percpu_nmi_buffer; + +/* + * The buffer used is dependent on the context. There is a per cpu + * buffer for normal context, softirq contex, hard irq context and + * for NMI context. Thise allows for lockless recording. + * + * Note, if the buffers failed to be allocated, then this returns NULL + */ +static char *get_trace_buf(void) +{ + struct trace_buffer_struct *percpu_buffer; + struct trace_buffer_struct *buffer; + + /* + * If we have allocated per cpu buffers, then we do not + * need to do any locking. + */ + if (in_nmi()) + percpu_buffer = trace_percpu_nmi_buffer; + else if (in_irq()) + percpu_buffer = trace_percpu_irq_buffer; + else if (in_softirq()) + percpu_buffer = trace_percpu_sirq_buffer; + else + percpu_buffer = trace_percpu_buffer; + + if (!percpu_buffer) + return NULL; + + buffer = per_cpu_ptr(percpu_buffer, smp_processor_id()); + + return buffer->buffer; +} + +static int alloc_percpu_trace_buffer(void) +{ + struct trace_buffer_struct *buffers; + struct trace_buffer_struct *sirq_buffers; + struct trace_buffer_struct *irq_buffers; + struct trace_buffer_struct *nmi_buffers; + + buffers = alloc_percpu(struct trace_buffer_struct); + if (!buffers) + goto err_warn; + + sirq_buffers = alloc_percpu(struct trace_buffer_struct); + if (!sirq_buffers) + goto err_sirq; + + irq_buffers = alloc_percpu(struct trace_buffer_struct); + if (!irq_buffers) + goto err_irq; + + nmi_buffers = alloc_percpu(struct trace_buffer_struct); + if (!nmi_buffers) + goto err_nmi; + + trace_percpu_buffer = buffers; + trace_percpu_sirq_buffer = sirq_buffers; + trace_percpu_irq_buffer = irq_buffers; + trace_percpu_nmi_buffer = nmi_buffers; + + return 0; + + err_nmi: + free_percpu(irq_buffers); + err_irq: + free_percpu(sirq_buffers); + err_sirq: + free_percpu(buffers); + err_warn: + WARN(1, "Could not allocate percpu trace_printk buffer"); + return -ENOMEM; +} + +void trace_printk_init_buffers(void) +{ + static int buffers_allocated; + + if (buffers_allocated) + return; + + if (alloc_percpu_trace_buffer()) + return; + + pr_info("ftrace: Allocated trace_printk buffers\n"); + + buffers_allocated = 1; +} + /** * trace_vbprintk - write binary msg to tracing buffer * */ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) { - static arch_spinlock_t trace_buf_lock = - (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; - static u32 trace_buf[TRACE_BUF_SIZE]; - struct ftrace_event_call *call = &event_bprint; struct ring_buffer_event *event; struct ring_buffer *buffer; struct trace_array *tr = &global_trace; - struct trace_array_cpu *data; struct bprint_entry *entry; unsigned long flags; - int disable; - int cpu, len = 0, size, pc; + char *tbuffer; + int len = 0, size, pc; if (unlikely(tracing_selftest_running || tracing_disabled)) return 0; @@ -1526,43 +1596,36 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) pc = preempt_count(); preempt_disable_notrace(); - cpu = raw_smp_processor_id(); - data = tr->data[cpu]; - disable = atomic_inc_return(&data->disabled); - if (unlikely(disable != 1)) + tbuffer = get_trace_buf(); + if (!tbuffer) { + len = 0; goto out; + } - /* Lockdep uses trace_printk for lock tracing */ - local_irq_save(flags); - arch_spin_lock(&trace_buf_lock); - len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args); + len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args); - if (len > TRACE_BUF_SIZE || len < 0) - goto out_unlock; + if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0) + goto out; + local_save_flags(flags); size = sizeof(*entry) + sizeof(u32) * len; buffer = tr->buffer; event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, flags, pc); if (!event) - goto out_unlock; + goto out; entry = ring_buffer_event_data(event); entry->ip = ip; entry->fmt = fmt; - memcpy(entry->buf, trace_buf, sizeof(u32) * len); + memcpy(entry->buf, tbuffer, sizeof(u32) * len); if (!filter_check_discard(call, entry, buffer, event)) { ring_buffer_unlock_commit(buffer, event); ftrace_trace_stack(buffer, flags, 6, pc); } -out_unlock: - arch_spin_unlock(&trace_buf_lock); - local_irq_restore(flags); - out: - atomic_dec_return(&data->disabled); preempt_enable_notrace(); unpause_graph_tracing(); @@ -1588,58 +1651,53 @@ int trace_array_printk(struct trace_array *tr, int trace_array_vprintk(struct trace_array *tr, unsigned long ip, const char *fmt, va_list args) { - static arch_spinlock_t trace_buf_lock = __ARCH_SPIN_LOCK_UNLOCKED; - static char trace_buf[TRACE_BUF_SIZE]; - struct ftrace_event_call *call = &event_print; struct ring_buffer_event *event; struct ring_buffer *buffer; - struct trace_array_cpu *data; - int cpu, len = 0, size, pc; + int len = 0, size, pc; struct print_entry *entry; - unsigned long irq_flags; - int disable; + unsigned long flags; + char *tbuffer; if (tracing_disabled || tracing_selftest_running) return 0; + /* Don't pollute graph traces with trace_vprintk internals */ + pause_graph_tracing(); + pc = preempt_count(); preempt_disable_notrace(); - cpu = raw_smp_processor_id(); - data = tr->data[cpu]; - disable = atomic_inc_return(&data->disabled); - if (unlikely(disable != 1)) + + tbuffer = get_trace_buf(); + if (!tbuffer) { + len = 0; goto out; + } - pause_graph_tracing(); - raw_local_irq_save(irq_flags); - arch_spin_lock(&trace_buf_lock); - len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); + len = vsnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); + if (len > TRACE_BUF_SIZE) + goto out; + local_save_flags(flags); size = sizeof(*entry) + len + 1; buffer = tr->buffer; event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, - irq_flags, pc); + flags, pc); if (!event) - goto out_unlock; + goto out; entry = ring_buffer_event_data(event); entry->ip = ip; - memcpy(&entry->buf, trace_buf, len); + memcpy(&entry->buf, tbuffer, len); entry->buf[len] = '\0'; if (!filter_check_discard(call, entry, buffer, event)) { ring_buffer_unlock_commit(buffer, event); - ftrace_trace_stack(buffer, irq_flags, 6, pc); + ftrace_trace_stack(buffer, flags, 6, pc); } - - out_unlock: - arch_spin_unlock(&trace_buf_lock); - raw_local_irq_restore(irq_flags); - unpause_graph_tracing(); out: - atomic_dec_return(&data->disabled); preempt_enable_notrace(); + unpause_graph_tracing(); return len; } @@ -1652,14 +1710,9 @@ EXPORT_SYMBOL_GPL(trace_vprintk); static void trace_iterator_increment(struct trace_iterator *iter) { - /* Don't allow ftrace to trace into the ring buffers */ - ftrace_disable_cpu(); - iter->idx++; if (iter->buffer_iter[iter->cpu]) ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); - - ftrace_enable_cpu(); } static struct trace_entry * @@ -1669,17 +1722,12 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, struct ring_buffer_event *event; struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu]; - /* Don't allow ftrace to trace into the ring buffers */ - ftrace_disable_cpu(); - if (buf_iter) event = ring_buffer_iter_peek(buf_iter, ts); else event = ring_buffer_peek(iter->tr->buffer, cpu, ts, lost_events); - ftrace_enable_cpu(); - if (event) { iter->ent_size = ring_buffer_event_length(event); return ring_buffer_event_data(event); @@ -1769,11 +1817,8 @@ void *trace_find_next_entry_inc(struct trace_iterator *iter) static void trace_consume(struct trace_iterator *iter) { - /* Don't allow ftrace to trace into the ring buffers */ - ftrace_disable_cpu(); ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts, &iter->lost_events); - ftrace_enable_cpu(); } static void *s_next(struct seq_file *m, void *v, loff_t *pos) @@ -1862,16 +1907,12 @@ static void *s_start(struct seq_file *m, loff_t *pos) iter->cpu = 0; iter->idx = -1; - ftrace_disable_cpu(); - if (cpu_file == TRACE_PIPE_ALL_CPU) { for_each_tracing_cpu(cpu) tracing_iter_reset(iter, cpu); } else tracing_iter_reset(iter, cpu_file); - ftrace_enable_cpu(); - iter->leftover = 0; for (p = iter; p && l < *pos; p = s_next(m, p, &l)) ; @@ -2332,15 +2373,13 @@ static struct trace_iterator * __tracing_open(struct inode *inode, struct file *file) { long cpu_file = (long) inode->i_private; - void *fail_ret = ERR_PTR(-ENOMEM); struct trace_iterator *iter; - struct seq_file *m; - int cpu, ret; + int cpu; if (tracing_disabled) return ERR_PTR(-ENODEV); - iter = kzalloc(sizeof(*iter), GFP_KERNEL); + iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter)); if (!iter) return ERR_PTR(-ENOMEM); @@ -2397,32 +2436,15 @@ __tracing_open(struct inode *inode, struct file *file) tracing_iter_reset(iter, cpu); } - ret = seq_open(file, &tracer_seq_ops); - if (ret < 0) { - fail_ret = ERR_PTR(ret); - goto fail_buffer; - } - - m = file->private_data; - m->private = iter; - mutex_unlock(&trace_types_lock); return iter; - fail_buffer: - for_each_tracing_cpu(cpu) { - if (iter->buffer_iter[cpu]) - ring_buffer_read_finish(iter->buffer_iter[cpu]); - } - free_cpumask_var(iter->started); - tracing_start(); fail: mutex_unlock(&trace_types_lock); kfree(iter->trace); - kfree(iter); - - return fail_ret; + seq_release_private(inode, file); + return ERR_PTR(-ENOMEM); } int tracing_open_generic(struct inode *inode, struct file *filp) @@ -2458,11 +2480,10 @@ static int tracing_release(struct inode *inode, struct file *file) tracing_start(); mutex_unlock(&trace_types_lock); - seq_release(inode, file); mutex_destroy(&iter->mutex); free_cpumask_var(iter->started); kfree(iter->trace); - kfree(iter); + seq_release_private(inode, file); return 0; } @@ -2974,7 +2995,14 @@ int tracer_init(struct tracer *t, struct trace_array *tr) return t->init(tr); } -static int __tracing_resize_ring_buffer(unsigned long size) +static void set_buffer_entries(struct trace_array *tr, unsigned long val) +{ + int cpu; + for_each_tracing_cpu(cpu) + tr->data[cpu]->entries = val; +} + +static int __tracing_resize_ring_buffer(unsigned long size, int cpu) { int ret; @@ -2985,19 +3013,32 @@ static int __tracing_resize_ring_buffer(unsigned long size) */ ring_buffer_expanded = 1; - ret = ring_buffer_resize(global_trace.buffer, size); + ret = ring_buffer_resize(global_trace.buffer, size, cpu); if (ret < 0) return ret; if (!current_trace->use_max_tr) goto out; - ret = ring_buffer_resize(max_tr.buffer, size); + ret = ring_buffer_resize(max_tr.buffer, size, cpu); if (ret < 0) { - int r; + int r = 0; + + if (cpu == RING_BUFFER_ALL_CPUS) { + int i; + for_each_tracing_cpu(i) { + r = ring_buffer_resize(global_trace.buffer, + global_trace.data[i]->entries, + i); + if (r < 0) + break; + } + } else { + r = ring_buffer_resize(global_trace.buffer, + global_trace.data[cpu]->entries, + cpu); + } - r = ring_buffer_resize(global_trace.buffer, - global_trace.entries); if (r < 0) { /* * AARGH! We are left with different @@ -3019,14 +3060,21 @@ static int __tracing_resize_ring_buffer(unsigned long size) return ret; } - max_tr.entries = size; + if (cpu == RING_BUFFER_ALL_CPUS) + set_buffer_entries(&max_tr, size); + else + max_tr.data[cpu]->entries = size; + out: - global_trace.entries = size; + if (cpu == RING_BUFFER_ALL_CPUS) + set_buffer_entries(&global_trace, size); + else + global_trace.data[cpu]->entries = size; return ret; } -static ssize_t tracing_resize_ring_buffer(unsigned long size) +static ssize_t tracing_resize_ring_buffer(unsigned long size, int cpu_id) { int cpu, ret = size; @@ -3042,12 +3090,19 @@ static ssize_t tracing_resize_ring_buffer(unsigned long size) atomic_inc(&max_tr.data[cpu]->disabled); } - if (size != global_trace.entries) - ret = __tracing_resize_ring_buffer(size); + if (cpu_id != RING_BUFFER_ALL_CPUS) { + /* make sure, this cpu is enabled in the mask */ + if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) { + ret = -EINVAL; + goto out; + } + } + ret = __tracing_resize_ring_buffer(size, cpu_id); if (ret < 0) ret = -ENOMEM; +out: for_each_tracing_cpu(cpu) { if (global_trace.data[cpu]) atomic_dec(&global_trace.data[cpu]->disabled); @@ -3078,7 +3133,8 @@ int tracing_update_buffers(void) mutex_lock(&trace_types_lock); if (!ring_buffer_expanded) - ret = __tracing_resize_ring_buffer(trace_buf_size); + ret = __tracing_resize_ring_buffer(trace_buf_size, + RING_BUFFER_ALL_CPUS); mutex_unlock(&trace_types_lock); return ret; @@ -3102,7 +3158,8 @@ static int tracing_set_tracer(const char *buf) mutex_lock(&trace_types_lock); if (!ring_buffer_expanded) { - ret = __tracing_resize_ring_buffer(trace_buf_size); + ret = __tracing_resize_ring_buffer(trace_buf_size, + RING_BUFFER_ALL_CPUS); if (ret < 0) goto out; ret = 0; @@ -3128,8 +3185,8 @@ static int tracing_set_tracer(const char *buf) * The max_tr ring buffer has some state (e.g. ring->clock) and * we want preserve it. */ - ring_buffer_resize(max_tr.buffer, 1); - max_tr.entries = 1; + ring_buffer_resize(max_tr.buffer, 1, RING_BUFFER_ALL_CPUS); + set_buffer_entries(&max_tr, 1); } destroy_trace_option_files(topts); @@ -3137,10 +3194,17 @@ static int tracing_set_tracer(const char *buf) topts = create_trace_option_files(current_trace); if (current_trace->use_max_tr) { - ret = ring_buffer_resize(max_tr.buffer, global_trace.entries); - if (ret < 0) - goto out; - max_tr.entries = global_trace.entries; + int cpu; + /* we need to make per cpu buffer sizes equivalent */ + for_each_tracing_cpu(cpu) { + ret = ring_buffer_resize(max_tr.buffer, + global_trace.data[cpu]->entries, + cpu); + if (ret < 0) + goto out; + max_tr.data[cpu]->entries = + global_trace.data[cpu]->entries; + } } if (t->init) { @@ -3642,30 +3706,82 @@ out_err: goto out; } +struct ftrace_entries_info { + struct trace_array *tr; + int cpu; +}; + +static int tracing_entries_open(struct inode *inode, struct file *filp) +{ + struct ftrace_entries_info *info; + + if (tracing_disabled) + return -ENODEV; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + info->tr = &global_trace; + info->cpu = (unsigned long)inode->i_private; + + filp->private_data = info; + + return 0; +} + static ssize_t tracing_entries_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - struct trace_array *tr = filp->private_data; - char buf[96]; - int r; + struct ftrace_entries_info *info = filp->private_data; + struct trace_array *tr = info->tr; + char buf[64]; + int r = 0; + ssize_t ret; mutex_lock(&trace_types_lock); - if (!ring_buffer_expanded) - r = sprintf(buf, "%lu (expanded: %lu)\n", - tr->entries >> 10, - trace_buf_size >> 10); - else - r = sprintf(buf, "%lu\n", tr->entries >> 10); + + if (info->cpu == RING_BUFFER_ALL_CPUS) { + int cpu, buf_size_same; + unsigned long size; + + size = 0; + buf_size_same = 1; + /* check if all cpu sizes are same */ + for_each_tracing_cpu(cpu) { + /* fill in the size from first enabled cpu */ + if (size == 0) + size = tr->data[cpu]->entries; + if (size != tr->data[cpu]->entries) { + buf_size_same = 0; + break; + } + } + + if (buf_size_same) { + if (!ring_buffer_expanded) + r = sprintf(buf, "%lu (expanded: %lu)\n", + size >> 10, + trace_buf_size >> 10); + else + r = sprintf(buf, "%lu\n", size >> 10); + } else + r = sprintf(buf, "X\n"); + } else + r = sprintf(buf, "%lu\n", tr->data[info->cpu]->entries >> 10); + mutex_unlock(&trace_types_lock); - return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); + ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); + return ret; } static ssize_t tracing_entries_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { + struct ftrace_entries_info *info = filp->private_data; unsigned long val; int ret; @@ -3680,7 +3796,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, /* value is in KB */ val <<= 10; - ret = tracing_resize_ring_buffer(val); + ret = tracing_resize_ring_buffer(val, info->cpu); if (ret < 0) return ret; @@ -3689,6 +3805,16 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, return cnt; } +static int +tracing_entries_release(struct inode *inode, struct file *filp) +{ + struct ftrace_entries_info *info = filp->private_data; + + kfree(info); + + return 0; +} + static ssize_t tracing_total_entries_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) @@ -3700,7 +3826,7 @@ tracing_total_entries_read(struct file *filp, char __user *ubuf, mutex_lock(&trace_types_lock); for_each_tracing_cpu(cpu) { - size += tr->entries >> 10; + size += tr->data[cpu]->entries >> 10; if (!ring_buffer_expanded) expanded_size += trace_buf_size >> 10; } @@ -3734,7 +3860,7 @@ tracing_free_buffer_release(struct inode *inode, struct file *filp) if (trace_flags & TRACE_ITER_STOP_ON_FREE) tracing_off(); /* resize the ring buffer to 0 */ - tracing_resize_ring_buffer(0); + tracing_resize_ring_buffer(0, RING_BUFFER_ALL_CPUS); return 0; } @@ -3933,9 +4059,10 @@ static const struct file_operations tracing_pipe_fops = { }; static const struct file_operations tracing_entries_fops = { - .open = tracing_open_generic, + .open = tracing_entries_open, .read = tracing_entries_read, .write = tracing_entries_write, + .release = tracing_entries_release, .llseek = generic_file_llseek, }; @@ -4387,6 +4514,9 @@ static void tracing_init_debugfs_percpu(long cpu) trace_create_file("stats", 0444, d_cpu, (void *) cpu, &tracing_stats_fops); + + trace_create_file("buffer_size_kb", 0444, d_cpu, + (void *) cpu, &tracing_entries_fops); } #ifdef CONFIG_FTRACE_SELFTEST @@ -4716,7 +4846,7 @@ static __init int tracer_init_debugfs(void) (void *) TRACE_PIPE_ALL_CPU, &tracing_pipe_fops); trace_create_file("buffer_size_kb", 0644, d_tracer, - &global_trace, &tracing_entries_fops); + (void *) RING_BUFFER_ALL_CPUS, &tracing_entries_fops); trace_create_file("buffer_total_size_kb", 0444, d_tracer, &global_trace, &tracing_total_entries_fops); @@ -4955,6 +5085,10 @@ __init static int tracer_alloc_buffers(void) if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL)) goto out_free_buffer_mask; + /* Only allocate trace_printk buffers if a trace_printk exists */ + if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt) + trace_printk_init_buffers(); + /* To save memory, keep the ring buffer size to its minimum */ if (ring_buffer_expanded) ring_buf_size = trace_buf_size; @@ -4973,7 +5107,6 @@ __init static int tracer_alloc_buffers(void) WARN_ON(1); goto out_free_cpumask; } - global_trace.entries = ring_buffer_size(global_trace.buffer); if (global_trace.buffer_disabled) tracing_off(); @@ -4986,7 +5119,6 @@ __init static int tracer_alloc_buffers(void) ring_buffer_free(global_trace.buffer); goto out_free_cpumask; } - max_tr.entries = 1; #endif /* Allocate the first page for all buffers */ @@ -4995,6 +5127,11 @@ __init static int tracer_alloc_buffers(void) max_tr.data[i] = &per_cpu(max_tr_data, i); } + set_buffer_entries(&global_trace, ring_buf_size); +#ifdef CONFIG_TRACER_MAX_TRACE + set_buffer_entries(&max_tr, 1); +#endif + trace_init_cmdlines(); register_tracer(&nop_trace); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 1bcdbec95a11..a7d28e033a96 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -136,6 +136,7 @@ struct trace_array_cpu { atomic_t disabled; void *buffer_page; /* ring buffer spare */ + unsigned long entries; unsigned long saved_latency; unsigned long critical_start; unsigned long critical_end; @@ -157,7 +158,6 @@ struct trace_array_cpu { */ struct trace_array { struct ring_buffer *buffer; - unsigned long entries; int cpu; int buffer_disabled; cycle_t time_start; @@ -831,6 +831,8 @@ extern struct list_head ftrace_events; extern const char *__start___trace_bprintk_fmt[]; extern const char *__stop___trace_bprintk_fmt[]; +void trace_printk_init_buffers(void); + #undef FTRACE_ENTRY #define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter) \ extern struct ftrace_event_call \ diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index 6fd4ffd042f9..a9077c1b4ad3 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -51,6 +51,10 @@ void hold_module_trace_bprintk_format(const char **start, const char **end) const char **iter; char *fmt; + /* allocate the trace_printk per cpu buffers */ + if (start != end) + trace_printk_init_buffers(); + mutex_lock(&btrace_mutex); for (iter = start; iter < end; iter++) { struct trace_bprintk_fmt *tb_fmt = lookup_format(*iter); |
