[GIT PULL] ring-buffer: Updates for 5.10

From: Steven Rostedt
Date: Fri Oct 23 2020 - 12:07:55 EST


Linus,

ring-buffer fix:

The success return value of ring_buffer_resize() is stated to be zero,
and checked that way. But it is incorrectly returning the size allocated.

Also, a fix to a comment.


Please pull the latest trace-v5.10-3 tree, which can be found at:


git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
trace-v5.10-3

Tag SHA1: 9e0dd73391c8f6cf700fe46cd65415b41676ba16
Head SHA1: e1981f75d398c0afe83c8ffa4e5864f037967409


Qiujun Huang (2):
ring-buffer: Return 0 on success from ring_buffer_resize()
ring-buffer: Update the description for ring_buffer_wait

----
kernel/trace/ring_buffer.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
---------------------------
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 15bf28b13e50..7f45fd9d5a45 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -793,7 +793,7 @@ static void rb_wake_up_waiters(struct irq_work *work)
* ring_buffer_wait - wait for input to the ring buffer
* @buffer: buffer to wait on
* @cpu: the cpu buffer to wait on
- * @full: wait until a full page is available, if @cpu != RING_BUFFER_ALL_CPUS
+ * @full: wait until the percentage of pages are available, if @cpu != RING_BUFFER_ALL_CPUS
*
* If @cpu == RING_BUFFER_ALL_CPUS then the task will wake up as soon
* as data is added to any of the @buffer's cpu buffers. Otherwise
@@ -1952,18 +1952,18 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
{
struct ring_buffer_per_cpu *cpu_buffer;
unsigned long nr_pages;
- int cpu, err = 0;
+ int cpu, err;

/*
* Always succeed at resizing a non-existent buffer:
*/
if (!buffer)
- return size;
+ return 0;

/* Make sure the requested buffer exists */
if (cpu_id != RING_BUFFER_ALL_CPUS &&
!cpumask_test_cpu(cpu_id, buffer->cpumask))
- return size;
+ return 0;

nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);

@@ -2119,7 +2119,7 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
}

mutex_unlock(&buffer->mutex);
- return size;
+ return 0;

out_err:
for_each_buffer_cpu(buffer, cpu) {