HP-UX 11i Internals

The proc Table

For a process to exist (at least from the point of view of the kernel), a proc data structure must be placed in the system proc table. Prior to HP-UX 11i, the proc table was a static array, the kernel pointer *proc defined its beginning, and the size was tuned via the kernel parameter nproc. The proc table is one of the largest tables in the kernel (at HP-UX 11.00, each proc structure was 700 bytes), and tuning nproc could significantly alter the size of the kernel. This effect was amplified, since many additional kernel data structures were sized in proportion to nproc.

With the release of HP-UX 11i, the proc table has become dynamic (see Figure 5-2). This means that individual proc structures are allocated from kernel memory ...