Talk:Distcc

DistCC Needs a Tuning Section
If I'm not mistaken, DistCC pretty much ignores the "/etc/make.conf" or "/etc/portage/make.conf" MAKEOPTS variable, and spawns the jobs as needed until the jobs fallback to the local box (not via network) for compiling. (So tinkering with the MAKEOPTS variable is likely not needed, as this variable is usually already setup on most Gentoo boxes.)

Think I figured how to properly tune DistCC. Add the following "--jobs" option to the server or helper box performing the compiling. Typically the "--jobs" option will mirror the MAKEOPTS variable within the "/etc/portage/make.conf" file or CPU's+1. Notice that the DistCC server (or helper box) now has spawned ten distccd threads. (ie. ps ax |grep distccd)

/etc/conf.d/distccd: DISTCCD_OPTS="--port 3632 --log-level warning --log-file /var/log/distccd.log -N 15 --allow 127.0.0.1 --allow 192.168.1.0/24 --jobs 10"

On the client box, the "/etc/distcc/hosts" for designating the DistCC server (or helper box); the jobs can be limited, but not designated more jobs? /etc/distcc/hosts 192.168.1.5/5

Per DistCC manual; by defaults, DistCC spawns four threads or four jobs (plus one) for per each host listed within the /etc/distcc/hosts file.

I'm still slightly confused here. And likely the "--jobs 10" option needs to be integrated into both the client and server/helper boxes. And then the /etc/distcc/hosts limits the job number as necessary by using the /num suffix option to the server address?

--Roger (talk) 22:26, 1 May 2014 (UTC)

DistCC Pump Mode
Article jumps right into pump mode. Might be nice to have a very very brief one sentence explaining pump mode. ie. "Distcc's pump mode accelerates remote compilation with distcc by also distributing preprocessing to the servers. (ie. man pump)"

The only other noteworthy item within the pump manual is; "Note that distcc's pump-mode assumes that sources files will not be modified during the lifetime of the include server, so modifying source files during a build may cause inconsistent results." Of which, I don't think I've ever personally seen source files modified during compilation, unless somebody remotely logged into a version control system while the sources were being recompiled. Being a source Linux based distribution, I still don't think the later is worth much concern? --Roger (talk) 18:15, 21 January 2015 (UTC)

Also, no mention of requiring to add ",cpp,lzo" (ie. 192.168.1.2/10,cpp,lzo) to the hosts lines within the /etc/distcc/hosts file! This is a requisite for DistCC pump mode! The example 192.168.1.2/10,cpp,lzo first specifies a remote compiler host, then limit sending 10 jobs max to the remote host compiler, including sending cpp jobs with lzo compression for which the later two cpp/lzo options are required for pump mode to work. Else, the user will see warnings and errors upon pump emerge! --Roger (talk) 19:05, 21 January 2015 (UTC)

Command for obtaining -march=native options
Previously, this command was listed as the mechanism for obtaining the CFLAGS equivent to -march=native:

However, it has some flaws. Something valuable that the -march=native option obtains is information about the processor's cache (including the L1 line size). However, the one-liner I've replaced it with I can't promise will be 100% accurate on all archs, since I'm filtering out the hordes of -mno-* flags that gcc puts in there since 4.7 or so. I'm betting on gcc using these flags to add features to a base march, but if it uses a -mno-* flag to remove a feature from any arch, then this will be broken.

Maybe what we really need is a mechanism for the distcc client to insert these flags and relieve the user from having to fish them out.

Daniel Santos (talk) 22:42, 26 January 2015 (UTC)