Re: [PATCH 08/15] tracing: Introduce names for ring buffers

[Steven Rostedt]

On Wed, 13 Dec 2023 00:04:45 +0000
Alexander Graf <graf@xxxxxxxxxx> wrote:

> With KHO (Kexec HandOver), we want to preserve trace buffers across
> kexec. To carry over their state between kernels, the kernel needs a
> common handle for them that exists on both sides. As handle we introduce
> names for ring buffers. In a follow-up patch, the kernel can then use
> these names to recover buffer contents for specific ring buffers.
> 

Is there a way to use the trace_array name instead?

The trace_array is the structure that represents each tracing instance. And
it already has a name field. And if you can get the associated ring buffer
from that too.

struct trace_array *tr;

	tr->array_buffer.buffer

	tr->name

When you do: mkdir /sys/kernel/tracing/instance/foo

You create a new trace_array instance where tr->name = "foo" and allocates
the buffer for it as well.

-- Steve