On Fri, 7 Aug 2026 10:43:12 +0100 Vincent Donnefort <[email protected]> wrote:
> On Fri, Aug 07, 2026 at 09:14:26AM +0100, Vincent Donnefort wrote: > > On Fri, Aug 07, 2026 at 11:18:08AM +0900, Masami Hiramatsu wrote: > > > 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) > > > > __rb_allocate_pages() in ring_buffer_resize() would call for a persistent > > buffer > > rb_range_buffer(), which IIUC, is just reusing the same ring buffer pages > > as the > > one already in the persistent buffer. > > I have just tried and if reducing the size works, increasing fails in both > rb_set_head_page() and rb_insert_pages() with a warning, which I believe is > expected. > > We could improve that, but it feels like it is a lot of work for a meaningless > feature which we should just disable? Resizing a persistent ring buffer to a smaller size may be allowed, but I see no point in increasing the size. Making it smaller should allow us to give back a portion of the persistent ring buffer for general usage. -- Steve
