Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[pandora-kernel.git] / kernel / trace / ring_buffer.c

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f2f821a..f5b7b5c 100644 (file)
--- 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 */
@@ -2660,6 +2673,58 @@ rb_num_of_entries(struct ring_buffer_per_cpu *cpu_buffer)
                (local_read(&cpu_buffer->overrun) + cpu_buffer->read);
 }
 
+/**
+ * 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];
+       raw_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;
+       raw_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
@@ -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);