Solaris SunOS 5.1 Specifics

Solaris provides automatic data collection tools, for System Activity, in addition to the normal set of Unix performance monitoring facilities mentioned above. sar/sadc and sa[12] all work to provide reports on accumulated statistics including: verbatim98 There are added complications in solaris due to processes consisting potentially of LWPs and threads. This means that their behaviour could be more complex and will depend on the number of processors on even a single system. This needs further study. For programatic access to process status, traditionally, Unix has relied on the kernel symbol table and read access to /dev/kmem through the kvm_ routines: verbatim99 SVID introduced the ;SPM_quot;/proc;SPM_quot; abstraction, which permits more portable access to process status through a special filesystem. Solaris provides access to process and LWP information through ioctl's to /proc, for instance returning the (C) structure illustrated in figure #tbprocstat#2506>.

Figure: Process State Information

Clearly, accessing this information across all processes would provide <#2510#> extremely<#2510#> detailed view of the load characteristics of the system - it remains to be studied in practice how expensive this would be, and what sampling techniques could be applied to reduce the overhead while minimizing inaccuracies.