On Tue, Nov 23, 2010 at 12:04:12AM +0800, Américo Wang wrote: > On Mon, Nov 22, 2010 at 07:33:51AM +0800, Shaohui Zheng wrote: > >On Sun, Nov 21, 2010 at 11:03:45PM +0800, Américo Wang wrote: > >> > >> >From your documentation above, it looks like you are trying > >> to move one CPU between nodes? > >Yes, you are correct. With cpu probe/release interface, you can hot-remove a > >CPU from a node, and hot-add it to another node. > > > Can I also move the CPU to another node _after_ it is hot-added? > Or I have to hot-remove it first and then hot-add it again? of course you can. you can hot-remove it via cpu/release interface, and then hot-add it by cpu/probe interface. With the cpu probe/reelase interface, we can design some stress test cases to hot add/remove cpu by script. > > >> > >> >+ cpu_hpe=on/off > >> >+ Enable/disable cpu hotplug emulation with software method. when cpu_hpe=on, > >> >+ sysfs provides probe/release interface to hot add/remove cpu dynamically. > >> >+ this option is disabled in default. > >> >+ > >> > >> Why not just a CONFIG? IOW, why do we need to make another boot > >> parameter for this? > >Only the developer or QA will use the emulator, we did not want to change the > >default action for common user who does not care the hotplug emulator, so we > >use a kernel parameter as a switch. The common user is not aware the existence > >of the emulator. > > > > I think it is also useful to other Linux users, e.g. after I > boot with "maxcpus=1", I can still bring the rest 3 CPU's > back without reboot. You understand it very well. the probe/release on ppc is already implemented, but for x86, it is a feature missing, so we finished it with these patches. > > Thanks. > > -- > Live like a child, think like the god. > -- Thanks & Regards, Shaohui -- 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>