Add release notes for 6.12.1

[ghc-hetmet.git] / docs / users_guide / profiling.xml

diff --git a/docs/users_guide/profiling.xml b/docs/users_guide/profiling.xml
index 9a1f289..0410d9e 100644 (file)
--- a/docs/users_guide/profiling.xml
+++ b/docs/users_guide/profiling.xml
@@ -33,7 +33,9 @@
     <listitem>
       <para> Run your program with one of the profiling options, eg.
       <literal>+RTS -p -RTS</literal>.  This generates a file of
-      profiling information.</para>
+      profiling information.  Note that multi-processor execution
+      (e.g. <literal>+RTS -N2</literal>) is not supported while
+      profiling.</para>
       <indexterm><primary><option>-p</option></primary><secondary>RTS
       option</secondary></indexterm>
     </listitem>
@@ -264,6 +266,22 @@ MAIN                     MAIN             0    0.0   0.0    100.0 100.0
       far to the right as possible when parsing. (SCC stands for "Set
       Cost Centre").</para>
 
+      <para>Here is an example of a program with a couple of SCCs:</para>
+
+<programlisting>
+main :: IO ()
+main = do let xs = {-# SCC "X" #-} [1..1000000]
+          let ys = {-# SCC "Y" #-} [1..2000000]
+          print $ last xs
+          print $ last $ init xs
+          print $ last ys
+          print $ last $ init ys
+</programlisting>
+
+      <para>which gives this heap profile when run:</para>
+
+      <imagedata fileref="prof_scc"/>
+
     </sect2>
 
     <sect2 id="prof-rules">
@@ -507,6 +525,11 @@ x = nfib 25
       </listitem>
     </orderedlist>
 
+    <para>You might also want to take a look
+      at <ulink url="http://www.haskell.org/haskellwiki/Hp2any">hp2any</ulink>,
+      a more advanced suite of tools (not distributed with GHC) for
+      displaying heap profiles.</para>
+
     <sect2 id="rts-options-heap-prof">
       <title>RTS options for heap profiling</title>
 
@@ -1256,7 +1279,7 @@ to re-read its input file:
     <indexterm><primary>hpc</primary></indexterm>
 
     <para>
-      Code coverage tools allow a programer to determine what parts of
+      Code coverage tools allow a programmer to determine what parts of
       their code have been actually executed, and which parts have
       never actually been invoked.  GHC has an option for generating
       instrumented code that records code coverage as part of the