James Knott wrote:
"Addressing physical memory above 4 GB requires more than the 32 bits of address offered by the standard operating mode of Intel (32-bit) processors. To this end, Intel introduced the 36-bit physical addressing mode called PAE, starting with the Intel Pentium Pro processor.
Isn't that more or less what I started this thread with?
Because processes running in these environments have 32-bit pointers, the operating system must manage and present PAE's 36 bits of address in such a way that the applications can practically use it.
Which is what I am ALSO saying. The application does not go beyond the 4Gb address space, the operating system (in our case Linux) does that for the application.
"3. Application Windowing A PAE-enabled operating system can introduce an API to allow a properly coded application access to physical memory anywhere in the system, even though it may be above 4 GB. Ideally, the API to allocate "high" physical memory and create or move the window should be quick and simple to code. This is highly advantageous for applications that require fast access to large amounts of data in memory.
1) do we have such an API in Linux? 2) is it necessary except for those rare cases where a single process needs to address more than 4Gb? I still maintain that (at least in Linux) using PAE is something for the kernel to do, not the application, with the possible exception of applications needing more than 4Gb of memory. /Per Jessen, Zürich -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com