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

From: Rusty Russell
Date: Tue Dec 02 2008 - 18:09:49 EST


On Wednesday 03 December 2008 08:06:54 Andrew Morton wrote:
> Steven Rostedt <rostedt@xxxxxxxxxxx> 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.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/