SPECweb99 Tuning Disclosure: For Digital UNIX 4.0F (updated 2/21/2000) ----------------------------------------------------------------------- Sysconfigtab Parameters: proc: maxusers - The maxusers attribute is used to tune several system parameters to increase the number of users who can theoretically use a system simultaneously. Changing the value of this attribute generates changes to the values of taskmax, threadmax, and min_free_vnodes, to name a few. Default value: 32 max-proc-per-user - The maximum limit of processes (tasks) a user can create. Zero indicates unlimited. (The superuser is not affected.) Default value: 64 max-threads-per-user - The maximum limit of threads a user can create. (The superuser is not affected.) Default value: 256 max-per-proc-address-space - max-per-proc-data-size - max-per-proc-stack-size - Maximum values for the current limits of the attributes per-proc-address-space, per-proc-data-size, and per-proc-stack-size. The current limits can be increased at run time by means of the setrlimit(2) system call or the ulimit(3) C library call. The current limits cannot be expanded beyond the values established by the "max-per-proc-*" attributes. Default value: max-per-proc-address-space = 1073741824 max-per-proc-data-size = 4398046511104 max-per-proc-stack-size = 33554432 per-proc-address-space - per-proc-data-size - per-proc-stack-size - The current upper limits of the respective resources. For example, a user stack cannot exceed the size set by the per-proc-stack-size attribute. Default value: per-proc-address-space = 1073741824 per-proc-data-size = 4398046511104 per-proc-stack-size = 2097152 socket: umc - Enables (1) or disables (0) the Unified Mbuf Cache (UMC) Default value: 0 sominconn - Minimum value for socket listen queue length limit (backlog). Silently overrides user-specified backlog when the user backlog is less than than the value of this attribute. Takes precedence over the somaxconn attribute. Default value: 0 somaxconn - Maximum value for socket listen queue length limit (backlog). Silently overrides user-specified backlog when the user backlog is greater than the value of this attribute. The sominconn attribute takes precedence. Default value: 1024 inet: ipqs - Number of IP processing queues. Default value: 1 tcbhashnum - Number of primary TCP hash table entries. Default value: 1 tcbhashsize - Sets the TCP control block hash table size. Default value: 32 tcp_sendspace - Default send buffer size for TCP sockets. Default value: 32765 tcp_recvspace - Default receive buffer size for TCP sockets. Default value: Default value: 32765 ipqmaxlen - Maximum length of the IP input queue (ipintrq) before input packets are dropped. Default value: 512 (packets) vm: ubc-maxpercent - Maximum percentage of physical memory that the UBC can use at one time. Default value 100 (percent). vm-mapentries - The maximum number of map entries that any process can use at any point in time. Each map entry describes one unique disjoint portion of a virtual address space. Default value: 200 vm-maxvas - The maximum amount of virtual address space that any user process can have at any point in time. Default value: 1073741824 vm-vpagemax - The maximum number of virtual pages within the address space for a process that can be given individual protection attributes (that is, protection attributes that differ from the protection attributes associated with the other pages in the address space). Default value: 16384 vfs: name-cache-hash-size Size of the hash chain table for the namei cache. Default value: 256 slots namei-cache-valid-time Amount of time a namei cache entry can remain in the cache before it is discarded. Default value: 1200 (seconds) advfs: AdvfsCacheMaxPercent - The percentage of system memory that is allocated to the AdvFS buffer cache. Default value: 7 (percent) AdvfsCacheHashSize - The size of the buffer cache hash table. At system initialization, AdvFS calculates the size of the hash table, unless overridden by this parameter. AdvfsPreallocAccess - The number of access structures allocated on the AdvFS access structure free list at system startup. The specified number will be adjusted to conform to the value of the AdvfsAccessMaxPercent attribute. Default value: 128 (access structures) net: netisrthreads - Number of network threads configured in a system. Default value: n (Based on the number of CPUs in a system. For a system with one processor, the value is 1. For a multiprocessing system, the value is 1 plus the number of processors.) netisrwakeupthreshold - Number of packets (packet threshold) above which another netisr thread is started. Default value: 1 (packet) Zeus 3.1.9 Tuning: ------------------ For details on the Zeus tuning parameters used please see: http://support.zeus.co.uk/faq/entries/tuning.html#31