speeding up buildworld/kernel

[Maxim Khitrov]

On Jan 24, 2008 4:05 PM, Erik Trulsson <ertr1013 at student.uu.se> wrote:
>
> On Thu, Jan 24, 2008 at 03:32:18PM -0500, Maxim Khitrov wrote:
> > On Jan 24, 2008 3:15 PM, Aryeh M. Friedman <aryeh.friedman at gmail.com> wrote:
> > > I update my sources at least once a day and do buildworld/kernel just
> > > as often... It seems some stuff that needs not be recompiled is on
> > > every single run for example gcc and kerbos.   I have NO_CLEAN in
> > > /etc/make.conf is there anything else I can do to speed stuff up...
> > > for ref here is my /etc/make.conf:
> > >
> > > CPUTYPE?=nocona
> > > KERNCONF=MONSTER
> > > NO_CLEAN=
> > > NO_LPR=
> > > # added by use.perl 2008-01-17 11:48:48
> > > PERL_VER=5.8.8
> > > PERL_VERSION=5.8.8
> > >
> > > - --
> > > Aryeh M. Friedman
> > > FloSoft Systems, Java Tool Developers
> > > Developer, not business, friendly
> > > http://www.flosoft-systems.com
> >
> > I might be wrong, but NO_CLEAN seems like a bad idea except in special
> > circumstances. Install ccache, but make sure you set
> > CCACHE_HASH_COMPILER environment variable to 1. That will make sure
> > that the cache stays valid if the compiler executable is overwritten
> > by an identical copy (as it would be on installworld). When the
> > compiler changes the cache will be repopulated on the next rebuild.
>
> You are indeed wrong.  NO_CLEAN will work fine almost all the time - except
> in special circumstances.  The few times it does not work one can always do
> a 'make clean' by hand first. (Or even faster: 'rm -fr /usr/obj/*')
> If you set WRKDIRPREFIX to some useful value you can do the same thing
> for the ports tree.
> Personally I always compile with -DNO_CLEAN and use 'rm -fr' to clean.
> I have never had problems originating with this.
>
> ccache is not very useful for buildworld, since among the first thing
> buildworld does is to build the compiler and then use the newly built
> compiler to compile the rest. I.e. the already installed compiler (which is
> the one ccache will handle) will not be used for most of the build thus
> removing almost all the advantage of ccache.
> It is supposed to be possible to use ccache for buildworld as well, but
> that would require a bit of hackery.

That's not true. I just ran `make buildworld buildkernel` on my
firewall. Here are ccache stats when the operation finished:

root at cerberus [/root]# ccache -s
cache directory                     /srv/.ccache
cache hit                          12056
cache miss                            38
called for link                      461
multiple source files                  1
not a C/C++ file                    1228
unsupported compiler option            7
files in cache                    117366
cache size                         679.6 Mbytes
max cache size                       2.0 Gbytes

Ccache is used through the entire build process and there is no
hackery involved. Just follow the directions for changing the compiler
to /usr/local/libexec/ccache/world-cc. On this Celeron D 1.8 GHz
machine rebuilding world and kernel takes 45 minutes and 40 seconds. I
don't recall exactly what it was without ccache, but I think it was
around 3 hours. Just make sure that you set the CCACHE_HASH_COMPILER
variable, otherwise it will assume that the compiler is different just
because its modification time has changed.

- Max