On Thu, 6 Aug 2026 22:13:01 +0100
Vincent Donnefort <[email protected]> wrote:
> Dynamically resizing a persistent ring buffer is not possible. Disable
> the feature.
Is it true? Of course there is meaningless to resize the persistent
ring buffer (because it makes the buffer none-persistent), we are currently
allows user to resize it (like for resizing unused persistent ring buffer)
Thank you,
>
> Fixes: be68d63a139b ("ring-buffer: Add ring_buffer_alloc_range()")
> Signed-off-by: Vincent Donnefort <[email protected]>
>
> diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
> index 8e2485bb3aa8..afe75ad2bbf2 100644
> --- a/kernel/trace/ring_buffer.c
> +++ b/kernel/trace/ring_buffer.c
> @@ -2528,6 +2528,8 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer,
> long nr_pages, int cpu)
> if (cpu_buffer->ring_meta->head_buffer)
> rb_meta_buffer_update(cpu_buffer, bpage);
> bpage->range = 1;
> +
> + atomic_inc(&cpu_buffer->resize_disabled);
> } else if (buffer->remote) {
> struct ring_buffer_desc *desc =
> ring_buffer_desc(buffer->remote->desc, cpu);
>
> --
> 2.55.0.654.g21b8a5bc05-goog
>
--
Masami Hiramatsu (Google) <[email protected]>
