oprofile: fix cpu buffer size

The unit of oprofile_cpu_buffer_size is in samples, but was allocated in bytes. This led to the allocation of too small cpu buffers. This patch recalculates the buffer size in bytes taking also the ring_buffer_event header size into account. Reported-by: Suravee Suthikulpanit <[email protected]> Signed-off-by: Robert Richter <[email protected]>
yshchan · May 7, 2009 · 54f2c84 · 54f2c84
1 parent 091438d
commit 54f2c84
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
@@ -78,16 +78,20 @@ void free_cpu_buffers(void)
 	op_ring_buffer_write = NULL;
 }
 
+#define RB_EVENT_HDR_SIZE 4
+
 int alloc_cpu_buffers(void)
 {
 	int i;
 
 	unsigned long buffer_size = oprofile_cpu_buffer_size;
+	unsigned long byte_size = buffer_size * (sizeof(struct op_sample) +
+						 RB_EVENT_HDR_SIZE);
 
-	op_ring_buffer_read = ring_buffer_alloc(buffer_size, OP_BUFFER_FLAGS);
+	op_ring_buffer_read = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS);
 	if (!op_ring_buffer_read)
 		goto fail;
-	op_ring_buffer_write = ring_buffer_alloc(buffer_size, OP_BUFFER_FLAGS);
+	op_ring_buffer_write = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS);
 	if (!op_ring_buffer_write)
 		goto fail;