Prints a message that will allow us to evaluate the number of pages allocated by each CPU buffer as well the main values that participate in its calculation. $ echo 0 > /sys/kernel/debug/tracing/tracing_on $ echo 4096 > /sys/kernel/debug/tracing/buffer_size_kb .... e.g. of output: PAGE_SIZE: 4096, BUF_PAGE_HDR_SIZE: 16, size: 4194304, nr_pages: 1029 Signed-off-by: Frank A. Cancio Bello <frank@xxxxxxxxxxxxxxxxxxxxxx> --- kernel/trace/ring_buffer.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 66358d66c933..c10b6bcb29b9 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1730,6 +1730,8 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, return size; nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE); + printk(KERN_ALERT "PAGE_SIZE: %lu, BUF_PAGE_HDR_SIZE: %lu, size: %lu, nr_pages: %ld", + PAGE_SIZE, BUF_PAGE_HDR_SIZE, size, nr_pages); /* we need a minimum of two pages */ if (nr_pages < 2) -- 2.17.1
