Re: [Xen-devel] [PATCH 0/2] Improvements with noreturn

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 25/11/13 11:47, George Dunlap wrote:
> On Mon, Nov 25, 2013 at 10:25 AM, Andrew Cooper
> <andrew.cooper3@xxxxxxxxxx> wrote:
>> Make better use of noreturn.  It allows optimising compilers to produce more
>> efficient code.
>>
>> George:
>>   I request that this is included for 4.4 - It is no functional change, but
>>   quite a nice improvement in terms of code size.
> No functional change *if compilers are correct*.  If they're not, for
> any reason, it will be very difficult to actually catch between now
> and the release.
>
> I'm not inclined to think that a reduction of 6k is a big enough
> improvement to take the risk at this point.
>
>  -George

Patch 1 is literally just textual replacement, cleaning up its current
uses in the codebase.

Patch 2 applies its use to more functions in the codebase.

While I agree that it is "No functional change if compilers are
correct", this kind of paranoia could be applied to any and every patch
we consider taking.  Anyway, Linux uses it far more than we do at the
moment.

As for difficulty to catch regressions, I would disagree.  Failures to
reboot correctly will not pass the oss test, and the other alternative
is failures to crash correctly.

~Andrew

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel