diff options
Diffstat (limited to 'kernel/trace/ring_buffer.c')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 39 |
1 files changed, 32 insertions, 7 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 9ed509a015d..0ef7b4b2a1f 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -5,7 +5,6 @@ */ #include <linux/ring_buffer.h> #include <linux/trace_clock.h> -#include <linux/ftrace_irq.h> #include <linux/spinlock.h> #include <linux/debugfs.h> #include <linux/uaccess.h> @@ -669,7 +668,7 @@ static struct list_head *rb_list_head(struct list_head *list) * the reader page). But if the next page is a header page, * its flags will be non zero. */ -static int inline +static inline int rb_is_head_page(struct ring_buffer_per_cpu *cpu_buffer, struct buffer_page *page, struct list_head *list) { @@ -1429,6 +1428,17 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) } EXPORT_SYMBOL_GPL(ring_buffer_resize); +void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val) +{ + mutex_lock(&buffer->mutex); + if (val) + buffer->flags |= RB_FL_OVERWRITE; + else + buffer->flags &= ~RB_FL_OVERWRITE; + mutex_unlock(&buffer->mutex); +} +EXPORT_SYMBOL_GPL(ring_buffer_change_overwrite); + static inline void * __rb_data_page_index(struct buffer_data_page *bpage, unsigned index) { @@ -1468,7 +1478,7 @@ static inline unsigned long rb_page_entries(struct buffer_page *bpage) return local_read(&bpage->entries) & RB_WRITE_MASK; } -/* Size is determined by what has been commited */ +/* Size is determined by what has been committed */ static inline unsigned rb_page_size(struct buffer_page *bpage) { return rb_page_commit(bpage); @@ -2162,11 +2172,19 @@ rb_reserve_next_event(struct ring_buffer *buffer, if (likely(ts >= cpu_buffer->write_stamp)) { delta = diff; if (unlikely(test_time_stamp(delta))) { + int local_clock_stable = 1; +#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK + local_clock_stable = sched_clock_stable; +#endif WARN_ONCE(delta > (1ULL << 59), - KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n", + KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n%s", (unsigned long long)delta, (unsigned long long)ts, - (unsigned long long)cpu_buffer->write_stamp); + (unsigned long long)cpu_buffer->write_stamp, + local_clock_stable ? "" : + "If you just came from a suspend/resume,\n" + "please switch to the trace global clock:\n" + " echo global > /sys/kernel/debug/tracing/trace_clock\n"); add_timestamp = 1; } } @@ -2914,7 +2932,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) /* * cpu_buffer->pages just needs to point to the buffer, it * has no specific buffer page to point to. Lets move it out - * of our way so we don't accidently swap it. + * of our way so we don't accidentally swap it. */ cpu_buffer->pages = reader->list.prev; @@ -3853,6 +3871,13 @@ int ring_buffer_read_page(struct ring_buffer *buffer, /* Need to copy one event at a time */ do { + /* We need the size of one event, because + * rb_advance_reader only advances by one event, + * whereas rb_event_ts_length may include the size of + * one or two events. + * We have already ensured there's enough space if this + * is a time extend. */ + size = rb_event_length(event); memcpy(bpage->data + pos, rpage->data + rpos, size); len -= size; @@ -3867,7 +3892,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer, event = rb_reader_event(cpu_buffer); /* Always keep the time extend and data together */ size = rb_event_ts_length(event); - } while (len > size); + } while (len >= size); /* update bpage */ local_set(&bpage->commit, pos); |