On Mon, 11 Dec 2023 12:51:52 -0500 Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > On Mon, 11 Dec 2023 21:31:34 +0900 > Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> wrote: > > > On Sun, 10 Dec 2023 22:54:47 -0500 > > Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > > > > From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx> > > > > > > The snapshot buffer is to mimic the main buffer so that when a snapshot is > > > needed, the snapshot and main buffer are swapped. When the snapshot buffer > > > is allocated, it is set to the minimal size that the ring buffer may be at > > > and still functional. When it is allocated it becomes the same size as the > > > main ring buffer, and when the main ring buffer changes in size, it should > > > do. > > > > nit: There seems two "when the snapshot buffer is allocated" case, maybe latter > > "it" means main buffer? > > I changed the paragraph to be: > > The snapshot buffer is to mimic the main buffer so that when a snapshot is > needed, the snapshot and main buffer are swapped. When the snapshot buffer > is allocated, it is set to the minimal size that the ring buffer may be at > and still functional. When it is allocated it becomes the same size as the > main ring buffer, and when the main ring buffer changes in size, the > snapshot should also change in size if it is allocated. Yeah, this makes clearer. > > > > > > > > > Currently, the resize only updates the snapshot buffer if it's used by the > > > current tracer (ie. the preemptirqsoff tracer). But it needs to be updated > > > anytime it is allocated. > > > > > > When changing the size of the main buffer, instead of looking to see if > > > the current tracer is utilizing the snapshot buffer, just check if it is > > > allocated to know if it should be updated or not. > > > > > > Also fix typo in comment just above the code change. > > > > > > > Looks good to me. > > > > Reviewed-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> > > Thanks! > > > > > BTW, the historical naming leads this kind of issues. > > Maybe we'd better to rename 'max_buffer' to 'snapshot_buffer'? > > Agreed. But that's a cleanup for another day. Hmm, maybe that too should be > marked as "KTODO"? Yes! > > https://lore.kernel.org/all/369bc919-1a1d-4f37-9cc9-742a86a41282@kadam.mountain/ > Ah, this is a good idea. > > There's a lot of things that we have been discussing on these ring-buffer > patches that could be KTODO items. Thanks, > > -- Steve -- Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
