chris@umcp-cs.UUCP (Chris Torek) (09/21/85)
In article <49600008@convexs> hosking@convexs.UUCP writes: [me] >> Since as distributed 4.2 has a per-process VM limit of 6M, you cannot >> allocate more than 4M with malloc. (Of course if you raise the VM >> limits you can get as much space as you like, provided you have lots >> of paging space.) [him] > It turns out to be pretty trivial to raise this limit if you have > source; mostly just changing a few parameters in /sys/h/dmap.h > around: DMMIN, DMMAX, DMTEXT, and NXDAD. Unfortunately, the proper > values to change them to are not intuitively obvious, and will depend > upon subtle things like the size of your swap space, etc. You will be happy to know that in 4.3BSD, changing VM limits is truly trivial (up to a point). Most of the constants are now in <machine/vmparam.h>, and you can increase MAXDSIZE or MAXTSIZE without fiddling with DMMIN and DMMAX in most cases. Also, the defaults on our alpha tape were 6M text, 6M data, 512K default stack, 6M max stack. DMMAX is defined as 4096, but will be trimmed down for better swap allocation if it is larger than necessary. -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 4251) UUCP: seismo!umcp-cs!chris CSNet: chris@umcp-cs ARPA: chris@maryland