Document default Linux autocommit behavior, and show workaround.

diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index 27feffde8b620cc6c01eab7d98aa0309b01b4871..02befb8480c572a8ff6fb6618fc453b268fe5b11 100644 (file)
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1,5 +1,5 @@
 
 
 
@@ -2780,6 +2780,16 @@ kernel.shmmax = 134217728
         /usr/src/linux/include/asm-xxx/shmpara
         m.h and /usr/src/linux/include/linux/sem.h.
        
+
+       
+        Linux has poor default memory overcommit behavior.  Rather than
+        failing if it can not reserve enough memory, it returns success, 
+        but later fails when the memory can't be mapped and terminates 
+        the application.  To prevent unpredictable process termination, use:
+
+sysctl -w vm.overcommit_memory=3
+
+