Re: Enable compiler optimization by default?

[Benjamin Mahler <bm...@apache.org>]

I won't -1 but please see below before proceeding.

This was the original behavior and this will bring it full circle :)
See the thread here, and the additional links:

http://markmail.org/thread/ylqbxezgz6rtb7v2
https://reviews.apache.org/r/26426/#comment_rc96919-56878
https://issues.apache.org/jira/browse/MESOS-1985

It would be great to include an understanding of this context along with
the proposal.

On Thu, Feb 18, 2016 at 10:59 AM, Joris Van Remoortere <
joris.van.remoortere@gmail.com> wrote:

> +1 (binding)
> with the condition that we fix the flag mixing problem between CXXFLAGS and
> --enable-optimize --enable-debug, even if it is to disallow it for now.
> I want to avoid surprising behavior with implicit flags such as optimize:
> passing irrelevant CXXFLAGS magically turns it into a debug build.
>
> On Thu, Feb 18, 2016 at 1:27 PM, Neil Conway <ne...@gmail.com>
> wrote:
>
> > Great! I created https://issues.apache.org/jira/browse/MESOS-4709 to
> > track this issue.
> >
> > Neil
> >
> > On Thu, Feb 18, 2016 at 12:43 AM, Jan Schlicht <ja...@mesosphere.io>
> wrote:
> > > +1
> > >
> > > On Thu, Feb 18, 2016 at 2:34 AM, Klaus Ma <kl...@gmail.com>
> > wrote:
> > >
> > >> +1;
> > >>
> > >> So our CI will also update to use optimisation flags, right?  We need
> to
> > >> highlight this in upgrade document to our user; I used to meet so
> > strange
> > >> behaviour after changing -O level.
> > >>
> > >> On Thu, Feb 18, 2016 at 8:51 AM James DeFelice <
> > james.defelice@gmail.com>
> > >> wrote:
> > >>
> > >> > +1
> > >> > On Feb 17, 2016 7:24 PM, "Neil Conway" <ne...@gmail.com>
> wrote:
> > >> >
> > >> > > Hi folks,
> > >> > >
> > >> > > At present, Mesos defaults to compiling with "-O0"; to enable
> > compiler
> > >> > > optimizations, the user needs to specify "--enable-optimize".
> > >> > >
> > >> > > I'd like to propose we change the default, for a few reasons:
> > >> > >
> > >> > > (1) The autoconf default for CFLAGS/CXXFLAGS is "-O2 -g".
> > Anecdotally,
> > >> > > I think most software packages compile with a reasonable level of
> > >> > > optimizations enabled by default.
> > >> > >
> > >> > > (2) I think we should make the default configure flags appropriate
> > for
> > >> > > end-users (rather than Mesos developers): developers will be
> > familiar
> > >> > > enough with Mesos to tune the configure flags according to their
> own
> > >> > > preferences.
> > >> > >
> > >> > > (3) The performance consequences of not enabling compiler
> > >> > > optimizations can be pretty severe: 5x in a benchmark I just ran,
> > and
> > >> > > we've seen between 2x and 30x (!) performance differences for some
> > >> > > real-world workloads.
> > >> > >
> > >> > > Neil
> > >> > >
> > >> >
> > >> --
> > >>
> > >> Regards,
> > >> ----
> > >> Da (Klaus), Ma (马达), PMP® | Advisory Software Engineer
> > >> IBM Platform Development & Support, STG, IBM GCG
> > >> +86-10-8245 4084 | madaxa@cn.ibm.com | http://k82.me
> > >>
> > >
> > >
> > >
> > > --
> > > *Jan Schlicht*
> > > Distributed Systems Engineer, Mesosphere
> >
>