Re: [PATCH] trace: Correct comments about list of pages in buffer
From: Steven Rostedt
Date: Thu Feb 16 2017 - 09:34:18 EST
On Thu, 16 Feb 2017 02:17:28 -0800
Joel Fernandes <joelaf@xxxxxxxxxx> wrote:
> Comments related to list of pages in the ring buffer seem to be incorrect.
> This patch corrects them.
> Signed-off-by: Joel Fernandes <joelaf@xxxxxxxxxx>
> kernel/trace/trace.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index d7449783987a..94d508c08c7e 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -262,11 +262,11 @@ unsigned long long ns2usecs(u64 nsec)
> * The global_trace is the descriptor that holds the tracing
> * buffers for the live tracing. For each CPU, it contains
> - * a link list of pages that will store trace entries. The
> - * page descriptor of the pages in the memory is used to hold
> - * the link list by linking the lru item in the page descriptor
> - * to each of the pages in the buffer per CPU.
Wow, that's a description of the very first (and poor) implementation
of the ring buffer.
> - *
> + * a link list of pages that will store trace entries.
> + * Each page is wrapped by a buffer_page descriptor which contains
> + * a list element used to hold the list of pages by linking with
> + * other list elements of other buffer_page descriptors (for each
> + * of the pages) in the ring buffer per CPU.
Actually, this comment doesn't even belong here anymore. The code lives
Want to send another patch that just nukes this?
> * For each active CPU there is a data field that holds the
> * pages for the buffer for that CPU. Each CPU has the same number
> * of pages allocated for its buffer.