[dpdk-dev] [PATCH v2 01/10] build: add an option to enable LTO build

[Thomas Monjalon]

20/09/2019 09:38, Ray Kinsella:
> 
> On 19/09/2019 16:16, Bruce Richardson wrote:
> > On Thu, Sep 19, 2019 at 02:28:04PM +0100, Ray Kinsella wrote:
> >>
> >>
> >> On 19/09/2019 13:35, Andrzej Ostruszka wrote:
> >>> On 9/18/19 3:32 PM, Ray Kinsella wrote:
> >> ...>
> >>> Compilation time is much longer.  In a normal hack|fix/compile/repeat
> >>> cycle with "compile" part being simple "make" the link time might be a
> >>> bit annoying.  So I imagine keeping LTO off for the most part of the dev
> >>> cycle and then at the end when doing release/cleanup turn LTO on - to
> >>> either get release build ready or to get some set of warnings that you
> >>> address before yet another attempt to release build.  
> >>
> >> Well look, I would say a few things.
> >>
> >> 1. I see build times going down dramatically with Meson/Ninja in any case.
> > 
> > In the general case yes, but mainly it helps if you have a large number of
> > cores. For anyone building in a CI with only a couple of cores, meson+ninja
> > isn't going to help much.
> > 
> > /Bruce
> > 
> 
> Very true, and I completely acknowledge that LTO adds compilation time.
> I would just like to see it in or out, not another build time option.

Please can we get some numbers to understand how longer it is?