runtime: simpler heap map, memory allocation

The old heap maps used a multilevel table, but that
was overkill: there are only 1M entries on a 32-bit
machine and we can arrange to use a dense address
range on a 64-bit machine.

The heap map is in bss.  The assumption is that if
we don't touch the pages they won't be mapped in.

Also moved some duplicated memory allocation
code out of the OS-specific files.

R=r
CC=golang-dev
http://codereview.appspot.com/4118042

1 files changed, 3 insertions, 1 deletions

diff --git a/test/run b/test/run
index 28d0caa0f..ec0195253 100755
--- a/test/run
+++ b/test/run
@@ -42,7 +42,9 @@ TMP2FILE=/tmp/gotest2-$$-$USER
 
 # don't run the machine out of memory: limit individual processes to 4GB.
 # on thresher, 3GB suffices to run the tests; with 2GB, peano fails.
-ulimit -v 4000000
+# Linux charges reserved but not mapped addresses to ulimit -v
+# so we have to use ulimit -m.
+ulimit -m 4000000
 
 # no core files please
 ulimit -c 0