[[project @ 2001-08-07 09:58:39 by simonmar]
simonmar**20010807095839
Document the GHCRTS env. var.
] {
hunk ./ghc/docs/users_guide/runtime_control.sgml 63
+
+ Setting global RTS options
+
+ RTS optionsfrom the environment
+ environment variablefor
+ setting RTS options
+
+ RTS options are also taken from the environment variable
+ GHCRTSGHCRTS
+ . For example, to set the maximum heap size
+ to 128M for all GHC-compiled programs (using an
+ sh-like shell):
+
+
+ GHCRTS='-M128m'
+ export GHCRTS
+
+
+ RTS options taken from the GHCRTS environment
+ variable can be overriden by options given on the command
+ line.
+
+
+
hunk ./ghc/docs/users_guide/runtime_control.sgml 88
- RTS options to control the garbage-collector
+ RTS options to control the garbage collector
hunk ./ghc/docs/users_guide/runtime_control.sgml 90
- RTS options, garbage-collection
+ garbage collectoroptions
+ RTS optionsgarbage collection
hunk ./ghc/docs/users_guide/runtime_control.sgml 121
+
+
+
+
+ RTS option
+
+ garbage collectioncompacting
+
+ compacting garbage collection
+
+
+ Use a compacting algorithm for collecting the oldest
+ generation. By default, the oldest generation is collected
+ using a copying algorithm; this option causes it to be
+ compacted in-place instead. The compaction algorithm is
+ slower than the copying algorithm, but the savings in memory
+ use can be considerable.
+
+ For a given heap size (using the
+ option), compaction can in fact reduce the GC cost by
+ allowing fewer GCs to be performed. This is more likely
+ when the ratio of live data to heap size is high, say
+ >30%.
+
+ NOTE: compaction doesn't currently work when a single
+ generation is requested using the
+ option.
+
}