On Wed, 2011-06-29 at 23:12 +0530, Ankita Garg wrote: > 4. The kernel must have a mechanism to maintain utilization > statistics pertaining to a piece of hardware, so that it can > trigger the hardware to power it off Having statistics like this would certainly be nice, but how important _is_ it? Is it really a show-stopper? There's some stuff today, like the NPT/EPT support in KVM where we don't even have visibility in to when a given page is referenced. It's also going to be a pain to track kernel references. On x86, our kernel linear mapping uses 1GB pages when it can, and those are greater than the 512MB granularity that we've been talking about here. It's even larger on powerpc. I'm also pretty sure we don't even _look_ at the referenced bits in the kernel page tables. We'll definitely need some infrastructure to do that. > 5. Being able to group these pieces of hardware for purpose of > higher savings. Do you really mean group, or do you mean "turn as many off as possible"? -- Dave -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>