Re: [PATCH 00/13] [PATCH RFC] Paravirtualized ticketlocks

From: Linus Torvalds
Date: Fri Sep 02 2011 - 16:28:48 EST


On Fri, Sep 2, 2011 at 1:07 PM, Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
>
> I don't know whether that fastpath code is small enough to consider
> inlining everywhere?

No.

There's no point in inlining something that ends up containing a
conditional function call: gcc will have to effectively save/restore
registers around that thing anyway, so you lose a lot of the
advantages of inlining. So I think it's better done as an out-of-line
function, which I thought we did for spinlocks anyway.

Also, do you run with CONFIG_OPTIMIZE_SIZE? Without that, gcc should
be smart enough to make a "likely()" case be a fall-through.

Linus
--
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/