Re: [PATCH 3/5] ring-buffer: read page interface

Rusty Russell
2008-12-02T23:09:48Z

On Wednesday 03 December 2008 08:06:54 Andrew Morton wrote:
> Steven Rostedt <rostedt@goodmis.org> wrote:
> > + if (!local_read(&cpu_buffer->reader_page->page->commit))
>
> Rusty (I think it was Rusty) has convincingly argued that local_t is
> irredeemably busted. I forget the details?

That was probably Christoph Lameter. The x86 implementation needs some love,
but the API seems reasonable.

On x86-32, the cpu_local_inc should be (as intended) turned into one insn.
That would be possible on 64 bit once we get zero-based percpu (as will World
Peace).

Cheers,
Rusty.