Kernel Tunable Parameters

maxdsize

Limits the data-segment size of 32-bit processes. Limiting data segment size prevents programs from using up all available memory; however, if your executable needs memory, make sure this parameter is set high enough.

maxdsiz_64bit

Limits the data-segment size of 64-bit processes.

dbc_max_pct

Sets the maximum size of the kernel dynamic buffer cache. A large buffer cache (used to cache file system data) is very important for overall performance of most systems; however, a large buffer cache can take memory away from user programs.

For machines with large amounts of memory you can free up memory for user processes by limiting the cache size to a couple of hundred megabytes (10% on a machine with 2GB RAM.