7121547: G1: High number mispredicted branches while iterating over the marking bitmap
Summary: There is a high number of mispredicted branches associated with calling BitMap::iteratate() from within CMBitMapRO::iterate(). Implement a version of CMBitMapRO::iterate() directly using inline-able routines.
Reviewed-by: tonyp, iveresov
README:
This file should be located at the top of the OpenJDK Mercurial root
repository. This root repository will include a "make" directory,
and a Makefile for building the entire OpenJDK.
A full OpenJDK repository set (forest) should also include the following
6 nested repositories:
"jdk", "hotspot", "langtools", "corba", "jaxws" and "jaxp".
There are also several source downloads for the jax* repositories that
will be needed.
This one root repository can be obtained with something like:
hg clone http://hg.openjdk.java.net/jdk8/jdk8 openjdk8
To make sure you have all the nested repositories, you can run the
get_source.sh script located in the same respository as this file:
cd openjdk8 && sh ./get_source.sh
People unfamiliar with Mercurial should read the first few chapters of
the Mercurial book: http://hgbook.red-bean.com/read/
See http://openjdk.java.net/ for more information about the OpenJDK.
Simple Build Instructions:
0. Get the necessary system software/packages installed on your system, see
http://hg.openjdk.java.net/jdk8/build/raw-file/tip/README-builds.html
1. If you don't have a jdk6 installed, download and install a JDK 6 from
http://java.sun.com/javase/downloads/index.jsp
Set the environment variable ALT_BOOTDIR to the location of JDK 6.
2. Check the sanity of doing a build with your current system:
make sanity
See README-builds.html if you run into problems.
3. Do a complete build of the OpenJDK:
make all
The resulting JDK image should be found in build/*/j2sdk-image
where make is GNU make 3.81 or newer, /usr/bin/make on Linux usually
is 3.81 or newer.
Complete details are available in README-builds.html.