Alan, with x86 virtualisation systems, do you mean VMware and/or Xen?
Just curious. Thanks, Juha Alan Cox wrote: >> But another view to the swap problem - or should we say the problem of >> sharing real memory: >> Can't we live without swap at all and use the cooperative memory management >> technique? >> You just define enough real memory for each linux instance to handle every >> peak (well, maybe almost) >> and they just use what they really need and release everything else to the >> common memory pool. >> You don't have to save free memory for new linux instances - all the memory >> which is free above VM >> for linuxes can be defined for them and they share it dynamically in the >> most effective way. > > This is essentially how the x86 virtualisation systems work. Pages are > "stolen" from one guest and handed to another. You still need swap > because you simply can't predict or guarantee that someone won't load all > the guests up at the same moment, but you can make better use of free > memory. > > The actual implementation used is to allocate memory in a guest which has > excess memory and in effect loan it to another guest based upon memory > pressure. As operating systems already allow the device drivers and > kernel to allocate memory, it turns out a model where each kernel appears > to allocate memory and sit on it (in fact loaning it to another guest) > keeps the changes to the guest OS as small as possible. > > Alan > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
