4.1-rc1 fails with O3 optimization

Andev debiandev at gmail.com
Tue Apr 28 01:41:07 EDT 2015


On Mon, Apr 27, 2015 at 9:00 PM, Bobby Powers <bobbypowers at gmail.com> wrote:
> Hello,
>
> Andev wrote:
>> I usually compile my kernel with an unsupported O3 option(why not? :).
>
> Because there have been publications that show on major benchmarks,
> the effects of -O3 are indistinguishable from noise:
> http://people.cs.umass.edu/~emery/pubs/Stabilizer-UMass-CS-TR2011-43.pdf
>
> Have you noticed that -O3 provides any performance benefits over -O2?
>

Look here: http://www.spinics.net/lists/kernel/msg1962561.html

Btw, this will help uncover problems in either gcc or the kernel for
sure. So no harm in trying!

-- 
Andev



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