On Wed, 2010-07-14 at 00:43 +0900, Minchan Kim wrote: > 3 is not a big deal than 2 about memory usage. > If the system use memory space fully(MAX_PHYSMEM_BITS 31), it just consumes > 1024(128 * 8) byte. So now I think best solution is 2. > > Russell. What do you think about it? I'm not Russell, but I'll tell you what I think. :) Make the sections 16MB. You suggestion to add the start/end pfns _doubles_ the size of the structure, and its size overhead. We have systems with a pretty tremendous amount of memory with 16MB sections. If you _really_ can't make the section size smaller, and the vast majority of the sections are fully populated, you could hack something in. We could, for instance, have a global list that's mostly readonly which tells you which sections need to be have their sizes closely inspected. That would work OK if, for instance, you only needed to check a couple of memory sections in the system. It'll start to suck if you made the lists very long. -- Dave -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>