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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
commitb4b7ff4b08e691656c9d77c758fc355833128ac0 (patch)
tree82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /kernel/trace/ring_buffer.c
parent35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff)
Linux-libre 4.4-gnupck-4.4-gnu
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c37
1 files changed, 19 insertions, 18 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index fc347f8b1..9c6045a27 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -829,7 +829,7 @@ rb_is_head_page(struct ring_buffer_per_cpu *cpu_buffer,
* writer is ever on it, the previous pointer never points
* back to the reader page.
*/
-static int rb_is_reader_page(struct buffer_page *page)
+static bool rb_is_reader_page(struct buffer_page *page)
{
struct list_head *list = page->list.prev;
@@ -1887,12 +1887,6 @@ rb_event_index(struct ring_buffer_event *event)
return (addr & ~PAGE_MASK) - BUF_PAGE_HDR_SIZE;
}
-static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
-{
- cpu_buffer->read_stamp = cpu_buffer->reader_page->page->time_stamp;
- cpu_buffer->reader_page->read = 0;
-}
-
static void rb_inc_iter(struct ring_buffer_iter *iter)
{
struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
@@ -2270,7 +2264,7 @@ rb_add_time_stamp(struct ring_buffer_event *event, u64 delta)
return skip_time_extend(event);
}
-static inline int rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
+static inline bool rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
struct ring_buffer_event *event);
/**
@@ -2498,7 +2492,7 @@ static inline void rb_event_discard(struct ring_buffer_event *event)
event->time_delta = 1;
}
-static inline int
+static inline bool
rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
struct ring_buffer_event *event)
{
@@ -2803,8 +2797,11 @@ rb_reserve_next_event(struct ring_buffer *buffer,
event = __rb_reserve_next(cpu_buffer, &info);
- if (unlikely(PTR_ERR(event) == -EAGAIN))
+ if (unlikely(PTR_ERR(event) == -EAGAIN)) {
+ if (info.add_timestamp)
+ info.length -= RB_LEN_TIME_EXTEND;
goto again;
+ }
if (!event)
goto out_fail;
@@ -3039,7 +3036,7 @@ int ring_buffer_write(struct ring_buffer *buffer,
}
EXPORT_SYMBOL_GPL(ring_buffer_write);
-static int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
+static bool rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
{
struct buffer_page *reader = cpu_buffer->reader_page;
struct buffer_page *head = rb_set_head_page(cpu_buffer);
@@ -3047,7 +3044,7 @@ static int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
/* In case of error, head will be NULL */
if (unlikely(!head))
- return 1;
+ return true;
return reader->read == rb_page_commit(reader) &&
(commit == reader ||
@@ -3626,7 +3623,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
/* Finally update the reader page to the new head */
cpu_buffer->reader_page = reader;
- rb_reset_reader_page(cpu_buffer);
+ cpu_buffer->reader_page->read = 0;
if (overwrite != cpu_buffer->last_overrun) {
cpu_buffer->lost_events = overwrite - cpu_buffer->last_overrun;
@@ -3636,6 +3633,10 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
goto again;
out:
+ /* Update the read_stamp on the first event */
+ if (reader && reader->read == 0)
+ cpu_buffer->read_stamp = reader->page->time_stamp;
+
arch_spin_unlock(&cpu_buffer->lock);
local_irq_restore(flags);
@@ -4267,7 +4268,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_reset);
* rind_buffer_empty - is the ring buffer empty?
* @buffer: The ring buffer to test
*/
-int ring_buffer_empty(struct ring_buffer *buffer)
+bool ring_buffer_empty(struct ring_buffer *buffer)
{
struct ring_buffer_per_cpu *cpu_buffer;
unsigned long flags;
@@ -4285,10 +4286,10 @@ int ring_buffer_empty(struct ring_buffer *buffer)
local_irq_restore(flags);
if (!ret)
- return 0;
+ return false;
}
- return 1;
+ return true;
}
EXPORT_SYMBOL_GPL(ring_buffer_empty);
@@ -4297,7 +4298,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_empty);
* @buffer: The ring buffer
* @cpu: The CPU buffer to test
*/
-int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
+bool ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
{
struct ring_buffer_per_cpu *cpu_buffer;
unsigned long flags;
@@ -4305,7 +4306,7 @@ int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
int ret;
if (!cpumask_test_cpu(cpu, buffer->cpumask))
- return 1;
+ return true;
cpu_buffer = buffer->buffers[cpu];
local_irq_save(flags);