I just want to interject here that I think, if memory serves me correctly, that SPARC has been 64 bit for 10~15 years, and so had LOTS of address space to map stuff. x86 brought a new restriction.
Regarding the practice of mapping files etc. into virtual memory that does not exist, now I understand why a 32 bit address space is viewed as restrictive. This is a powerful technique. I would be interested in understanding how it is done though... it somehow ties a file reference (inode? name?) to an address range. I assume when the range is accessed (since it does not exist) that a page fault is generated to fullfill the request, which then (for this to make sense) must have a short-circuit map to the disk blocks, which I assume would go through some disk cache in case they are in memory somewhere, else generate an IO request to disk... but what if the file was written, and so moved? Where would I read more about what is REALLY going on and how it works? Thanks, --Ray -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
