diff options
| -rw-r--r-- | include/linux/ring_buffer.h | 2 | ||||
| -rw-r--r-- | kernel/trace/ring_buffer.c | 70 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 13 |
3 files changed, 84 insertions, 1 deletions
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index b891de96000..67be0376d8e 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -154,6 +154,8 @@ void ring_buffer_record_enable(struct ring_buffer *buffer); void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); +unsigned long ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu); +unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_entries(struct ring_buffer *buffer); unsigned long ring_buffer_overruns(struct ring_buffer *buffer); unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 731201bf4ac..acf6b68dc4a 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -488,12 +488,14 @@ struct ring_buffer_per_cpu { struct buffer_page *reader_page; unsigned long lost_events; unsigned long last_overrun; + local_t entries_bytes; local_t commit_overrun; local_t overrun; local_t entries; local_t committing; local_t commits; unsigned long read; + unsigned long read_bytes; u64 write_stamp; u64 read_stamp; }; @@ -1708,6 +1710,7 @@ rb_handle_head_page(struct ring_buffer_per_cpu *cpu_buffer, * the counters. */ local_add(entries, &cpu_buffer->overrun); + local_sub(BUF_PAGE_SIZE, &cpu_buffer->entries_bytes); /* * The entries will be zeroed out when we move the @@ -1863,6 +1866,9 @@ rb_reset_tail(struct ring_buffer_per_cpu *cpu_buffer, event = __rb_page_index(tail_page, tail); kmemcheck_annotate_bitfield(event, bitfield); + /* account for padding bytes */ + local_add(BUF_PAGE_SIZE - tail, &cpu_buffer->entries_bytes); + /* * Save the original length to the meta data. * This will be used by the reader to add lost event @@ -2054,6 +2060,9 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, if (!tail) tail_page->page->time_stamp = ts; + /* account for these added bytes */ + local_add(length, &cpu_buffer->entries_bytes); + return event; } @@ -2076,6 +2085,7 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer, if (bpage->page == (void *)addr && rb_page_write(bpage) == old_index) { unsigned long write_mask = local_read(&bpage->write) & ~RB_WRITE_MASK; + unsigned long event_length = rb_event_length(event); /* * This is on the tail page. It is possible that * a write could come in and move the tail page @@ -2085,8 +2095,11 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer, old_index += write_mask; new_index += write_mask; index = local_cmpxchg(&bpage->write, old_index, new_index); - if (index == old_index) + if (index == old_index) { + /* update counters */ + local_sub(event_length, &cpu_buffer->entries_bytes); return 1; + } } /* could not discard */ @@ -2661,6 +2674,58 @@ rb_num_of_entries(struct ring_buffer_per_cpu *cpu_buffer) } /** + * ring_buffer_oldest_event_ts - get the oldest event timestamp from the buffer + * @buffer: The ring buffer + * @cpu: The per CPU buffer to read from. + */ +unsigned long ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu) +{ + unsigned long flags; + struct ring_buffer_per_cpu *cpu_buffer; + struct buffer_page *bpage; + unsigned long ret; + + if (!cpumask_test_cpu(cpu, buffer->cpumask)) + return 0; + + cpu_buffer = buffer->buffers[cpu]; + spin_lock_irqsave(&cpu_buffer->reader_lock, flags); + /* + * if the tail is on reader_page, oldest time stamp is on the reader + * page + */ + if (cpu_buffer->tail_page == cpu_buffer->reader_page) + bpage = cpu_buffer->reader_page; + else + bpage = rb_set_head_page(cpu_buffer); + ret = bpage->page->time_stamp; + spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags); + + return ret; +} +EXPORT_SYMBOL_GPL(ring_buffer_oldest_event_ts); + +/** + * ring_buffer_bytes_cpu - get the number of bytes consumed in a cpu buffer + * @buffer: The ring buffer + * @cpu: The per CPU buffer to read from. + */ +unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + unsigned long ret; + + if (!cpumask_test_cpu(cpu, buffer->cpumask)) + return 0; + + cpu_buffer = buffer->buffers[cpu]; + ret = local_read(&cpu_buffer->entries_bytes) - cpu_buffer->read_bytes; + + return ret; +} +EXPORT_SYMBOL_GPL(ring_buffer_bytes_cpu); + +/** * ring_buffer_entries_cpu - get the number of entries in a cpu buffer * @buffer: The ring buffer * @cpu: The per CPU buffer to get the entries from. @@ -3527,11 +3592,13 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer) cpu_buffer->reader_page->read = 0; local_set(&cpu_buffer->commit_overrun, 0); + local_set(&cpu_buffer->entries_bytes, 0); local_set(&cpu_buffer->overrun, 0); local_set(&cpu_buffer->entries, 0); local_set(&cpu_buffer->committing, 0); local_set(&cpu_buffer->commits, 0); cpu_buffer->read = 0; + cpu_buffer->read_bytes = 0; cpu_buffer->write_stamp = 0; cpu_buffer->read_stamp = 0; @@ -3918,6 +3985,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer, } else { /* update the entry counter */ cpu_buffer->read += rb_page_entries(reader); + cpu_buffer->read_bytes += BUF_PAGE_SIZE; /* swap the pages */ rb_init_page(bpage); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 01176788c38..b41907000bc 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4056,6 +4056,8 @@ tracing_stats_read(struct file *filp, char __user *ubuf, struct trace_array *tr = &global_trace; struct trace_seq *s; unsigned long cnt; + unsigned long long t; + unsigned long usec_rem; s = kmalloc(sizeof(*s), GFP_KERNEL); if (!s) @@ -4072,6 +4074,17 @@ tracing_stats_read(struct file *filp, char __user *ubuf, cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu); trace_seq_printf(s, "commit overrun: %ld\n", cnt); + cnt = ring_buffer_bytes_cpu(tr->buffer, cpu); + trace_seq_printf(s, "bytes: %ld\n", cnt); + + t = ns2usecs(ring_buffer_oldest_event_ts(tr->buffer, cpu)); + usec_rem = do_div(t, USEC_PER_SEC); + trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", t, usec_rem); + + t = ns2usecs(ring_buffer_time_stamp(tr->buffer, cpu)); + usec_rem = do_div(t, USEC_PER_SEC); + trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); + count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); kfree(s); |