Hi Eli, On Thu, May 19, 2011 at 1:39 PM, Eli Collins <e...@cloudera.com> wrote: > Thanks for contributing. Supporting ARM on Hadoop will require a > number of different changes right? Eg given that Hadoop currently > depends on some Sun-specific classes, and requires a Sun-compatible > JVM you'll have to work around this dependency somehow, there's not a > Sun JVM for ARM right?
Actually, there is a Sun JVM for ARM, and it works quite well: http://www.oracle.com/technetwork/java/embedded/downloads/index.html Currently, it's just a JRE, so you have to use another JDK for javac, etc., but I'm optimistic that we'll see a Sun Java SE JDK for ARM servers one of these days, given all the ARM server activity from Calxeda [http://www.theregister.co.uk/2011/03/14/calxeda_arm_server/], Marvell, and nVidia [http://www.channelregister.co.uk/2011/01/05/nvidia_arm_pc_server_chip/]. With the patches I submitted, Hadoop builds completely and nearly all of the Commons and HDFS unit tests pass with OpenJDK on ARM. (Some of the Map/Reduce unit tests have some crashes due to a bug in the OpenJDK build I'm using.) I need to re-run the unit tests with the Sun JRE and see if they pass; other tests/benchmarks have run much faster and more reliably with the Sun JRE, so I anticipate better results. I've run tests like TestDFSIO with the Sun JRE and have had no problems. > If there's a handful of additional changes then let's make an umbrella > jira for Hadoop ARM support and make the issues you've already filed > sub-tasks. You can ping me off-line on how to that if you want. > Supporting non-x86 processors and non-gcc compilers is an additional > maintenance burden on the project so it would be helpful to have an > end-game figured out so these patches don't bitrot in the meantime. I really don't anticipate any additional changes at this point. No Java or C++ code changes have been necessary; it's simply removing -m32 from CFLAGS/LDFLAGS and adding ARM to the list of processors in apsupport.m4 (which contains lots of other unsupported processors anyway). And just to be clear, pretty much everyone uses gcc for compilation on ARM, so supporting another compiler is unnecessary for this. I certainly don't want to increase maintenance burden at this point, especially given that data center-grade ARM servers are still in the prototype stage. OTOH, these changes seem pretty trivial to me, and allow other developers (particularly those evaluating ARM and those involved in the Ubuntu ARM Server 11.10 release this fall: https://blueprints.launchpad.net/ubuntu/+spec/server-o-arm-server) to get Hadoop up and running without having to patch the build. I'll follow up offline though, so I can better understand any concerns you may still have. Thanks, Trevor > On Tue, May 10, 2011 at 5:13 PM, Trevor Robinson <tre...@scurrilous.com> > wrote: >> Is the native build failing on ARM (where gcc doesn't support -m32) a >> known issue, and is there a workaround or fix pending? >> >> $ ant -Dcompile.native=true >> ... >> [exec] make all-am >> [exec] make[1]: Entering directory >> `/home/trobinson/dev/hadoop-common/build/native/Linux-arm-32' >> [exec] /bin/bash ./libtool --tag=CC --mode=compile gcc >> -DHAVE_CONFIG_H -I. -I/home/trobinson/dev/hadoop-common/src/native >> -I/usr/lib/jvm/java-6-openjdk/include >> -I/usr/lib/jvm/java-6-openjdk/include/linux >> -I/home/trobinson/dev/hadoop-common/src/native/src >> -Isrc/org/apache/hadoop/io/compress/zlib >> -Isrc/org/apache/hadoop/security -Isrc/org/apache/hadoop/io/nativeio/ >> -g -Wall -fPIC -O2 -m32 -g -O2 -MT ZlibCompressor.lo -MD -MP -MF >> .deps/ZlibCompressor.Tpo -c -o ZlibCompressor.lo `test -f >> 'src/org/apache/hadoop/io/compress/zlib/ZlibCompressor.c' || echo >> '/home/trobinson/dev/hadoop-common/src/native/'`src/org/apache/hadoop/io/compress/zlib/ZlibCompressor.c >> [exec] libtool: compile: gcc -DHAVE_CONFIG_H -I. >> -I/home/trobinson/dev/hadoop-common/src/native >> -I/usr/lib/jvm/java-6-openjdk/include >> -I/usr/lib/jvm/java-6-openjdk/include/linux >> -I/home/trobinson/dev/hadoop-common/src/native/src >> -Isrc/org/apache/hadoop/io/compress/zlib >> -Isrc/org/apache/hadoop/security -Isrc/org/apache/hadoop/io/nativeio/ >> -g -Wall -fPIC -O2 -m32 -g -O2 -MT ZlibCompressor.lo -MD -MP -MF >> .deps/ZlibCompressor.Tpo -c >> /home/trobinson/dev/hadoop-common/src/native/src/org/apache/hadoop/io/compress/zlib/ZlibCompressor.c >> -fPIC -DPIC -o .libs/ZlibCompressor.o >> [exec] make[1]: Leaving directory >> `/home/trobinson/dev/hadoop-common/build/native/Linux-arm-32' >> [exec] cc1: error: unrecognized command line option "-m32" >> [exec] make[1]: *** [ZlibCompressor.lo] Error 1 >> [exec] make: *** [all] Error 2 >> >> This closest issue I can find is >> https://issues.apache.org/jira/browse/HADOOP-6258 (Native compilation >> assumes gcc), as well as other issues regarding where and how to >> specify -m32/64. However, there doesn't seem to be a specific issue >> covering build failure on systems using gcc where the gcc target does >> not support -m32/64 (such as ARM). >> >> I've attached a patch that disables specifying -m$(JVM_DATA_MODEL) >> when $host_cpu starts with "arm". (For instance, host_cpu = armv7l for >> my system.) To any maintainers on this list, please let me know if >> you'd like me to open a new issue and/or attach this patch to an >> issue. >> >> Thanks, >> Trevor >> >
