build: turn on package parallel builds by default and fix descriptions.

By default, this is only used when building with make -j.

SVN-Revision: 33582
This commit is contained in:
Felix Fietkau 2012-09-28 18:09:41 +00:00
parent c53936bb4b
commit c02bd635b2
1 changed files with 12 additions and 15 deletions

View File

@ -296,23 +296,12 @@ menu "Global build settings"
config PKG_BUILD_PARALLEL
bool
prompt "Compile certain packages parallelized"
default n
default y
help
This adds a -jX option to certain packages that are known to
behave well for parallel build.
Note that this may overcommit CPU resources depending on the
-j level of the main make process, the number of package
submake jobs selected below and the number of actual CPUs present.
Example: If the main make is passed a -j4 and the submake -j
is also set to 4, we may end up with 16 parallel make processes
in the worst case.
You get maximum build performance, if you set the package build
jobs to the number of CPUs (cores) available and also start the main
make process with -jX, where X is the number of CPUs (cores).
However, make sure you have enough RAM available for
NR_CPUS to the power of two (NR_CPUS^2) make jobs.
behave well for parallel build. By default the package make processes
use the main jobserver, in which case this option only takes effect
when you add -jX to the make command.
If you are unsure, select N.
@ -325,6 +314,14 @@ menu "Global build settings"
This passes the main make process jobserver fds to package builds,
enabling full parallelization across different packages
Note that disabling this may overcommit CPU resources depending on the
-j level of the main make process, the number of package
submake jobs selected below and the number of actual CPUs present.
Example: If the main make is passed a -j4 and the submake -j
is also set to 4, we may end up with 16 parallel make processes
in the worst case.
config PKG_BUILD_JOBS
int
prompt "Number of package submake jobs (2-512)"