This patch set introduces a new chcpu tool to util-linux. chcpu lets a user configure CPUs. In this first version all that is possible is to enable or disable CPUs (set them online of offline). This is quite useful if you work a lot with virtual servers, since enabling and disabling cpus manually via sysfs becomes tiring. This first version is kept very simple so that I can easily change things based on feedback/criticism before I add more functionality. More features that I would like to add are - rescan cpus: trigger the kernel to trigger a rescan of cpus. Necessary because not all hypervisors on s390 generate a guest event if a new cpu becomes visible to a guest. - configure/deconfigure cpus: if cpus are offline the resources taken by the hypervisor can be freed if the cpus are deconfigured. Makes sense if a cpus are given dedicated to a logical partition. Deconfigured cpus can be given to other logical partitions. - set dispatch mode: if the underlying hypervisor is PR/SM (LPAR hypervisor) it is possible to configure it's scheduling algorithm for the virtual cpus of the own logical partition. Other architectures might add own features... Any feedback and/or criticism would be welcome. A usage example with a logical partition with 20 virtual cpus: [root@r35lp37]# chcpu --help Usage: chcpu [options] [cpu-list] Options: -h, --help print this help -e, --enable enable cpus -d, --disable disable cpus -v, --verbose explain what is being done -V, --version output version information and exit [root@r35lp37]# cat /proc/cpuinfo vendor_id : IBM/S390 # processors : 4 bogomips per cpu: 14367.00 features : esan3 zarch stfle msa ldisp eimm dfp etf3eh highgprs processor 1: version = 00, identification = 279F25, machine = 2817 processor 10: version = 00, identification = 279F25, machine = 2817 processor 11: version = 00, identification = 279F25, machine = 2817 processor 12: version = 00, identification = 279F25, machine = 2817 [root@r35lp37]# ./chcpu -v -e 0-20 CPU 0 enabled CPU 1 already enabled CPU 2 enabled CPU 3 enabled CPU 4 enabled CPU 5 enabled CPU 6 enabled CPU 7 enabled CPU 8 enabled CPU 9 enabled CPU 10 already enabled CPU 11 already enabled CPU 12 already enabled CPU 13 enabled CPU 14 enabled CPU 15 enabled CPU 16 enabled CPU 17 enabled CPU 18 enabled CPU 19 enabled CPU 20 does not exist [root@r35lp37]# cat /proc/cpuinfo vendor_id : IBM/S390 # processors : 20 bogomips per cpu: 14367.00 features : esan3 zarch stfle msa ldisp eimm dfp etf3eh highgprs processor 0: version = 00, identification = 279F25, machine = 2817 processor 1: version = 00, identification = 279F25, machine = 2817 processor 2: version = 00, identification = 279F25, machine = 2817 processor 3: version = 00, identification = 279F25, machine = 2817 processor 4: version = 00, identification = 279F25, machine = 2817 processor 5: version = 00, identification = 279F25, machine = 2817 processor 6: version = 00, identification = 279F25, machine = 2817 processor 7: version = 00, identification = 279F25, machine = 2817 processor 8: version = 00, identification = 279F25, machine = 2817 processor 9: version = 00, identification = 279F25, machine = 2817 processor 10: version = 00, identification = 279F25, machine = 2817 processor 11: version = 00, identification = 279F25, machine = 2817 processor 12: version = 00, identification = 279F25, machine = 2817 processor 13: version = 00, identification = 279F25, machine = 2817 processor 14: version = 00, identification = 279F25, machine = 2817 processor 15: version = 00, identification = 279F25, machine = 2817 processor 16: version = 00, identification = 279F25, machine = 2817 processor 17: version = 00, identification = 279F25, machine = 2817 processor 18: version = 00, identification = 279F25, machine = 2817 processor 19: version = 00, identification = 279F25, machine = 2817 Thanks, Heiko -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
