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-rw-r--r--kernel/trace/ftrace.c44
-rw-r--r--kernel/trace/ring_buffer.c248
-rw-r--r--kernel/trace/trace.c453
-rw-r--r--kernel/trace/trace.h4
-rw-r--r--kernel/trace/trace_printk.c4
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);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-14 05:35:55 +0000