Mailing List Archive

On 13/11/06 2:35 am, "Li, Xin B" <xin.b.li@intel.com> wrote:

> inline VMX functions since most of these functions are called just once.
>
> Signed-off-by: Xin Li <xin.b.li@intel.com>

Unless the function call is really hot (in an inner loop for example) I
don't believe that the performance benefit of inlining is measurable (or
maybe even exists at all). Against that there are the disadvantages that
debugging from a backtrace becomes much more of a pain (especially that
vmexit handler, which becomes *really* big!), and there's a tendency for
'inline' to spread around like a 'go faster' magic dust, applied to
functions where it really doesn't help. So I'm moderately inclined not to
take the inlining bits of this patch unless you strongly disagree.

-- Keir



_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

>
>Unless the function call is really hot (in an inner loop for example) I
>don't believe that the performance benefit of inlining is
>measurable (or
>maybe even exists at all). Against that there are the
>disadvantages that
>debugging from a backtrace becomes much more of a pain (especially that
>vmexit handler, which becomes *really* big!), and there's a
>tendency for
>'inline' to spread around like a 'go faster' magic dust, applied to
>functions where it really doesn't help. So I'm moderately
>inclined not to
>take the inlining bits of this patch unless you strongly disagree.
>

OK, let's not take it, such VMExits are small part of total VMExits.
-Xin

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel

On Mon, Nov 13, 2006 at 10:35:47AM +0800, Li, Xin B wrote:
> inline VMX functions since most of these functions are called just once.

gcc already inlines such static functions with -O2 and higher if it
thinks the output will be better.

Bastian

--
Lots of people drink from the wrong bottle sometimes.
-- Edith Keeler, "The City on the Edge of Forever",
stardate unknown

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel