Hey Jason, There are a bunch of "warn: instruction 'prefetch_nta' unimplemented" in atomic modes, during which the java benchmarks don't crash. However, there is no these kind of warnings during timing mode. Does it imply that unimplemented instructions don't cause the problem? Any clues or suggestions to debug these problems?
best, Da Zhang On Mon, Jul 16, 2018 at 1:32 PM Jason Lowe-Power <ja...@lowepower.com> wrote: > Hello, > > Are you seeing any warnings like "warn: Instruction XXX not implemented"? > > There are many X86 SIMD instructions that are currently unimplemented. I > would bet that your application is using some of those instructions and > getting 0's as the output instead of the correct value. > > The "right" way to solve this problem is to implement these instructions > (and we would really appreciate it if you contribute your fixes back on > https://gem5-review.googlesource.com. The other option is to recompile > your applications without SIMD extensions (e.g., -march=athlon64 or > whatever is the original x86-64 name in GCC). However, this likely requires > compiling all of the java runtime in your case. > > Cheers, > Jason > > On Mon, Jul 16, 2018 at 10:11 AM Da Zhang <d...@vt.edu> wrote: > >> To clarify, "SIGSEGV and null exceptions " happens to the benchmark >> suite, not gem5. Gem5 is running without errors. But in the >> system.pc.com_1.device files, I observe that most of the benchmarks crash >> due to SIGSEGV or null exceptions. >> Example: >> " >> >> x/system.pc.com_1.device >> >> >> >> buffers >> >> 1 # >> >> 2 # A fatal error has been detected by the Java Runtime Environment: >> >> 3 # >> >> 4 # SIGSEGV (0xb) at pc=0x00007f81d17742b7, pid=1474, >> tid=0x00007f81cf46d700 >> >> 5 # >> >> 6 # JRE version: Java(TM) SE Runtime Environment (8.0_171-b11) (build >> 1.8.0_171-b11) >> >> 7 # Java VM: Java HotSpot(TM) 64-Bit Server VM (25.171-b11 mixed mode >> linux-amd64 compressed oops) >> >> 8 # Problematic frame: >> >> 9 # J 1815 C2 >> org.apache.xml.serializer.ToHTMLStream.endElement(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)V >> (389 bytes) @ 0x00007f81d17742b7 [0x00007f81d1774280+0x37] >> >> >> >> 10 # >> >> 11 # >> " >> >> On Mon, Jul 16, 2018 at 11:39 AM Da Zhang <d...@vt.edu> wrote: >> >>> Hey guys, >>> >>> I am testing a java benchmark suite, dacapo, on gem5 with fs mode. >>> Unfortunately, I encounter a lot of SIGSEGV and null exceptions during >>> timing mode after restarting from the checkpoints. >>> I am using linux kernel v4.8.13 and ubuntu-server-16.04.1 with >>> oracle jdk v8.0_171-b11. To eliminate the influence of my modifications to >>> gem5 src/ and configs/, I re-download gem5 and checkout to commit >>> "ee2ffdc0fdb489767768e5273a4ccd7b51735c7c", which is the gem5 version I am >>> working on. The checkpoint was taken by using kvm cpu with 1 CPU and 16GB >>> memory. For the simulation, I use build/X86/gem5.opt (in order to enable >>> assertions) with fs mode (configs/example/fs.py). Other options include >>> "--cpu-type=DerivO3CPU -n 1 --mem-size=16GB --caches --l2cache >>> --l2_size=${L2SIZE}" (I try L2SIZE from 256KB to 8MB). I test with 100ms >>> warmup and 1ps real simulation time. There are no errors presented. But >>> with longer real simulation time, the benchmark suite crashes with >>> segfault. >>> I am able to run the dacapo benchmark suite in fs mode with kvm cpu, >>> without any segfaults or exceptions. I have some simple java benchmarks >>> tested; neither segfaults nor exceptions present. >>> Does anyone have suggestions or experience against these issues? >>> >>> best, >>> Da Zhang >>> >> _______________________________________________ >> gem5-users mailing list >> gem5-users@gem5.org >> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users > > _______________________________________________ > gem5-users mailing list > gem5-users@gem5.org > http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
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