On Fri, 8 Mar 2024 at 13:33, Steven Rostedt <rost...@goodmis.org> wrote:
>
> There's two layers:
>
> 1) the ring buffer has the above simple producer / consumer.
> Where the wake ups can happen at the point of where the buffer has
> the amount filled that the consumer wants to start consuming with.
>
> 2) The tracing layer; Here on close of a file, the consumers need to be
> woken up and not wait again. And just take whatever was there to finish
> reading.
>
> There's also another case that the ioctl() just kicks the current
> readers out, but doesn't care about new readers.
But that's the beauty of just using the wait_event() model.
Just add that "exit" condition to the condition.
So the above "complexity" is *literally* just changing the
(new = atomic_read_acquire(&my->seq)) != old
condition to
should_exit ||
(new = atomic_read_acquire(&my->seq)) != old
(replace "should_exit" with whatever that condition is, of course) and
the wait_event() logic will take care of the rest.
Linus
