[Xen-devel] Re: [PATCH 00/13] [PATCH RFC] Paravirtualized ticketlocks

[Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>]

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

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