7.3.2 Multiple Page Size Support

The Multiple Page Size Support (MPSS) feature allows a program to use different page sizes for different regions of virtual memory. The default Solaris page size is relatively small (8KB on UltraSPARC processors and 4KB on AMD64 Opteron processors). The default page size on a specific platform can be obtained with the Solaris OS command: pagesize . The -a option on this command lists all the supported page sizes. (See the pagesize(1) man page for details.)

Applications that suffer from too many TLB misses may experience a performance boost by using a larger page size. TLB misses can be measured using the Sun Performance Analyzer.

There are three ways to change the default page size for an application:

• Use the Solaris OS command ppgsz(1)

• Use MPSS specific environment variables. See the mpss.so.1(1) man page for details.

• Compile the application with the -xpagesize, -xpagesize_heap, or the -xpagesize_stack options. (See the compiler man pages for details.)