svn commit: r228143 - in head: . share/mk tools/build/options

[Steve Kargl]

On Tue, Dec 20, 2011 at 09:30:10PM -0800, Garrett Cooper wrote:
> On Tue, Dec 20, 2011 at 8:55 PM, Steve Kargl
> <sgk at troutmask.apl.washington.edu> wrote:
> > On Tue, Dec 20, 2011 at 06:45:07PM -0800, Doug Barton wrote:
> >> On 12/20/2011 18:29, Ben Kaduk wrote:
> >> > 2011/12/20 Doug Barton <dougb at freebsd.org>:
> >> >> On 12/20/2011 06:08, John Baldwin wrote:
> >> >>> The defaults for src.conf should be for the common case
> >> >>
> >> >> Agreed. The problem we seem to be missing here is that developers are
> >> >> not even statistically significant in measuring "the common case."
> >> >
> >> > "The common case" of what, though? ?"People using src.conf", or
> >> > "people rebuilding world", or just "people using FreeBSD"?
> >>
> >> The latter of course. The overwhelming majority of FreeBSD users will
> >> never use profiled libs, and in fact don't even know what they are. It's
> >> just useless space being taken up on every install. The defaults should
> >> be sensible for our users.
> >
> > OK, Doug, we get it! You don't like profiled libraries.
> > You don't use them, and by extension the 'common user'
> > does not use them.
> 
> The point that I was trying to drive home (that I think Doug is as well) is:
> - How many FreeBSD users are developers/performance/test engineers who
> care about this stuff being compiled into the base system?

Don't know.  I haven't seen a statistically meaningful poll of
the FreeBSD user base on which to draw an answer.  I suspect that
neither you nor Doug have seen such a poll.  

> - How many developers use gprof / profiled libraries?

Unfortunately, too few as evident by some of the code 
committed to src/.  Try timing buildworld WITH_CLANG and
WITHOUT_CLANG.

> - How many developers reroll their world by turning on WITH_PROFILE ?

As of the moment, none.  WITH_PROFILE is the default.

> - How often do you use gprof to profile binaries?

I use profiled libraries all time.  Of course, I'm interested in 
making my numerical codes run as fast as possible, and a profiler
does an amazing job of finding the bottlenecks.  You can also
ask bde and das about my forays into working on libm.

>     Smart defaults and better tuning are what we ultimately should be
> striving for, because again, WITH_PROFILE is a developer and not a
> end-user / administrator convenience. Those are the individuals we
> should be tailoring FreeBSD for -- not developers.

How many end-users/administrators do a buildworld and how often?
Neither the time to build profiled libraries nor the diskspace
used is significant.  Yes, I know you're going to posit that 
on slow ARM and embedded systems profiled libraries are undesirable.
I suspect that an ARM developer has more than just WITHOUT_PROFILE
her src.conf.

-- 
Steve