Messages in this thread | | | From | "Li, Haicheng" <> | Date | Sun, 21 Nov 2010 23:16:57 +0800 | Subject | RE: [8/8,v3] NUMA Hotplug Emulator: documentation |
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Américo Wang wrote: > On Wed, Nov 17, 2010 at 10:08:07AM +0800, shaohui.zheng@intel.com > wrote: >> +2) CPU hotplug emulation: >> + >> +The emulator reserve CPUs throu grub parameter, the reserved CPUs >> can be +hot-add/hot-remove in software method, it emulates the >> process of physical +cpu hotplug. + >> +When hotplug a CPU with emulator, we are using a logical CPU to >> emulate the CPU +socket hotplug process. For the CPU supported SMT, >> some logical CPUs are in the +same socket, but it may located in >> different NUMA node after we have emulator. +We put the logical CPU >> into a fake CPU socket, and assign it an unique +phys_proc_id. For >> the fake socket, we put one logical CPU in only. + + - to hide CPUs >> + - Using boot option "maxcpus=N" hide CPUs >> + N is the number of initialize CPUs >> + - Using boot option "cpu_hpe=on" to enable cpu hotplug emulation >> + when cpu_hpe is enabled, the rest CPUs will not be >> initialized + + - to hot-add CPU to node >> + $ echo nid > cpu/probe >> + >> + - to hot-remove CPU >> + $ echo nid > cpu/release >> + > > Again, we already have software CPU hotplug, > i.e. /sys/devices/system/cpu/cpuX/online.
online here is just for logical CPU online. what we're achieving here is to emulate physical CPU hotadd.
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