Subj : Re: virtual addresses To : comp.programming From : Brian Date : Tue Sep 27 2005 04:18 pm Randy Howard wrote: > Bill Cunningham wrote > (in article ): >> So the applications and the kernel space do not know what the real >> physical addresses are then. At least kernel space other than the memory >> manager? > That is typically true for applications (with rare exceptions), > but drivers and kernel code often know the physical address or > both, depending on what is being done down low. > If you think about it, there really isn't a reason why an > application needs to know the physical address. > In really high-end systems that support failover and RAID memory > systems, and even 'hot add' of memory to a running system, it is > extremely advantageous to not have apps tied to physical > addresses. There's one odd thing about virtual memory that is unexplainable. Or at least, no one has been able to explain it to me including a couple of research guys. Why haven't we outgrown page files / swap files? It was an early trick and kludge was it not? My first XP install was on a PIII with 256MB of memory. I suppose the page file was an additional 256MB. The computer had a practical upper memory limit of 512MB. I have the same version of XP running on a P4 with 2GB of memory today. 2GB is approximately 4x my original system's TOTAL available memory including it's page file. In other words, I have plenty o' memory without the disk. So why is the page file still there? .