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Diffstat (limited to 'doc/manual.cli')
| -rw-r--r-- | doc/manual.cli | 44 |
1 files changed, 34 insertions, 10 deletions
diff --git a/doc/manual.cli b/doc/manual.cli index a994e9f..2852064 100644 --- a/doc/manual.cli +++ b/doc/manual.cli @@ -181,23 +181,47 @@ sudo kvm \ A Build OS instances divides available CPUs and RAM (minus reserved, see below) into \i{slices} that are then \i{committed} to each instance of each -toolchain. If you don't expect your builds to utilize these resources at the -same time, then it may make sense to overcommit them to improve utilization. -The respective overcommit values can be specified as ratios with the -\c{buildos.cpu_overcommit} and \c{buildos.ram_overcommit} kernel command -line parameters. For example, given the following CPU overcommit: +toolchain. In case of CPU it normally makes sense to overcommit this resource +in order to improve utilization. This can be achieved by specifying the +overcommit values as a ratio with \c{buildos.cpu_overcommit}. For example, +given the following CPU overcommit: \ buildos.cpu_overcommit=3/2 \ -A Build OS machine with 8 CPUs (hardware threads) and three toolchains will +A Build OS machine with 8 CPUs (hardware threads) and three instances will assign 4 CPUs (\c{8 * 3/2 / 3}) to each slice. -It is also possible to reserve a number of CPUs and an amount of RAM to -Build OS with the \c{buildos.cpu_reserved} and \c{buildos.ram_reserved} -(in GB) kernel command line parameters. If unspecified, 4GB of RAM is -reserved by default. +It is also possible to specify CPU affinity with \c{buildos.cpu_affinity}. +For example, specifying: + +\ +buildos.cpu_affinity=2-9 +\ + +Will restrict the instances to only running on CPUs 2-9. + +It is possible to reserve a number of CPUs and an amount of RAM to Build OS +with the \c{buildos.cpu_reserved} and \c{buildos.ram_reserved} (in GiB) kernel +command line parameters. If unspecified, 4GiB of RAM is reserved by default. + +An amount of RAM can be reserved for auxiliary machines with +\c{buildos.ram_auxiliary}. This amount will also be divided into slices and +committed to each instance. + +Finally, if the total available RAM cannot be auto-detected, it can be +specified manually with \c{buildos.ram_total}. Here is a complete example of +specifying all the possible RAM values: + +\ +buildos.ram_total=64 +buildos.ram_reserved=4 +buildos.ram_auxiliary=12 +\ + +Assuming three instances, the configuration will assign 16GiB of build and +4GiB of auxiliary RAM to each instance and keep 4GiB reserved to Build OS. \h#config-storage|Storage| |