Re: [PATCH 1/6] ring-buffer: Prevent resizing of persistent ring buffer
Masami Hiramatsu (Google) <[email protected]>
| Newsgroups | org.kernel.vger.linux-kernel,org.kernel.vger.linux-trace-kernel |
|---|---|
| Message-ID | <[email protected]> |
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]>