On Wed, 17 Nov 2010, shaohui.zheng@xxxxxxxxx wrote: > From: Haicheng Li <haicheng.li@xxxxxxxxx> > > Add a sysfs entry "probe" under /sys/devices/system/node/: > > - to show all fake offlined nodes: > $ cat /sys/devices/system/node/probe > > - to hotadd a fake offlined node, e.g. nodeid is N: > $ echo N > /sys/devices/system/node/probe > This would be much more powerful if we just reserved an amount of memory at boot and then allowed users to hot-add a given amount with an non-online node id. Then we can test nodes of various sizes rather than being statically committed at boot. This should be fairly straight-forward by faking ACPI_SRAT_MEM_HOT_PLUGGABLE entries, for example. > Index: linux-hpe4/mm/Kconfig > =================================================================== > --- linux-hpe4.orig/mm/Kconfig 2010-11-15 17:13:02.443461606 +0800 > +++ linux-hpe4/mm/Kconfig 2010-11-15 17:21:05.535335091 +0800 > @@ -147,6 +147,21 @@ > depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE > depends on MIGRATION > > +config NUMA_HOTPLUG_EMU > + bool "NUMA hotplug emulator" > + depends on X86_64 && NUMA && MEMORY_HOTPLUG > + > + ---help--- > + > +config NODE_HOTPLUG_EMU > + bool "Node hotplug emulation" > + depends on NUMA_HOTPLUG_EMU && MEMORY_HOTPLUG > + ---help--- > + Enable Node hotplug emulation. The machine will be setup with > + hidden virtual nodes when booted with "numa=hide=N*size", where > + N is the number of hidden nodes, size is the memory size per > + hidden node. This is only useful for debugging. > + That's clearly wrong, but I don't see why this needs to be a new Kconfig option to begin with, can't we enable all of this functionality by default under CONFIG_NUMA_EMU && CONFIG_MEMORY_HOTPLUG? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>