X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=docs%2Fusers_guide%2Fruntime_control.xml;h=94995b3e8d27ff962a856ab67d34d5a245c60ff7;hb=7eb7ed723e9afbb2df4087108d07db5fbc47e7e1;hp=5039526c756a8307ed2dcbcd2496d3b3a593b84c;hpb=816b587f0057113ce9667f1f643d828d7abe2079;p=ghc-hetmet.git
diff --git a/docs/users_guide/runtime_control.xml b/docs/users_guide/runtime_control.xml
index 5039526..94995b3 100644
--- a/docs/users_guide/runtime_control.xml
+++ b/docs/users_guide/runtime_control.xml
@@ -130,6 +130,35 @@
own signal handlers.
+
+
+
+ RTS
+ option
+
+
+ WARNING: this option is for working around memory
+ allocation problems only. Do not use unless GHCi fails
+ with a message like “failed to mmap() memory below 2Gb”. If you need to use this option to get GHCi working
+ on your machine, please file a bug.
+
+
+
+ On 64-bit machines, the RTS needs to allocate memory in the
+ low 2Gb of the address space. Support for this across
+ different operating systems is patchy, and sometimes fails.
+ This option is there to give the RTS a hint about where it
+ should be able to allocate memory in the low 2Gb of the
+ address space. For example, +RTS -xm20000000
+ -RTS would hint that the RTS should allocate
+ starting at the 0.5Gb mark. The default is to use the OS's
+ built-in support for allocating memory in the low 2Gb if
+ available (e.g. mmap
+ with MAP_32BIT on Linux), or
+ otherwise -xm40000000.
+
+
+
@@ -448,6 +477,10 @@
fileRTS option
+
+
+ RTS option
+ These options produce runtime-system statistics, such
as the amount of time spent executing the program and in the
@@ -514,6 +547,27 @@
+ You can also get this in a more future-proof, machine readable
+ format, with -t --machine-readable:
+
+
+
+ [("bytes allocated", "36169392")
+ ,("num_GCs", "69")
+ ,("average_bytes_used", "603392")
+ ,("max_bytes_used", "1065272")
+ ,("num_byte_usage_samples", "2")
+ ,("peak_megabytes_allocated", "3")
+ ,("init_cpu_seconds", "0.00")
+ ,("init_wall_seconds", "0.00")
+ ,("mutator_cpu_seconds", "0.02")
+ ,("mutator_wall_seconds", "0.02")
+ ,("GC_cpu_seconds", "0.07")
+ ,("GC_wall_seconds", "0.07")
+ ]
+
+
+
If you use the -s flag then, when your
program finishes, you will see something like this (the exact
details will vary depending on what sort of RTS you have, e.g.