[ruby-core:104050] [Ruby master Bug#17871] TestGCCompact#test_ast_compacts test failing again

Issue #17871 has been updated by tenderlovemaking (Aaron Patterson).


xtkoba (Tee KOBAYASHI) wrote in #note-6:
> user:mame wrote in #note-4:
> > I'm unsure why the fix addressed the issue of #17306.
> 
> This is because after #17306 was fixed the commit commit:32b7dcfb56a417c1d1c354102351fc1825d653bf changed the behavior of `{,un}lock_page_body` so that they call `mprotect(2)` for an explicit compaction, regardless of the page size.

Ya, that's correct.  Even manual compaction requires the mprotect read barrier.  Basically we need to disable compaction on platforms that don't support it.  I'll make a fix.

----------------------------------------
Bug #17871: TestGCCompact#test_ast_compacts test failing again
https://bugs.ruby-lang.org/issues/17871#change-92188

* Author: jaruga (Jun Aruga)
* Status: Open
* Priority: Normal
* Backport: 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN
----------------------------------------
This issue was found by @mame yesterday on our new Power 9 server. I would like to open the ticket.

The test failure was reported and fixed on the #17306 6 months ago.
However on the latest master `adcbae8d49ec04d365ce13274783b1495c3c7d0e`, Power 9 (ppc64le) Ubuntu focal, I see the TestGCCompact#test_ast_compacts test fails.

```
$ lscpu | head -3
Architecture:                    ppc64le
Byte Order:                      Little Endian
CPU(s):                          8

$ lscpu | grep ^Model
Model:                           2.2 (pvr 004e 1202)
Model name:                      POWER9 (architected), altivec supported

$ uname -m
ppc64le

$ cat /etc/os-release | head -3
NAME="Ubuntu"
VERSION="20.04.2 LTS (Focal Fossa)"
ID=ubuntu

$ gcc --version
gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ autoconf
$ ./configure \
  --prefix=${HOME}/local/ruby-master-adcbae8 \
  --enable-shared
$ make
$ make install
$ make check 2>&1 | tee check.log
...
<internal:gc>:213: [BUG] Couldn't unprotect page 0x00000a1b33ba8000
ruby 3.1.0dev (2021-05-19T05:24:01Z master adcbae8d49) [powerpc64le-linux]

-- Control frame information -----------------------------------------------
c:0031 p:0003 s:0174 e:000173 METHOD <internal:gc>:213
c:0030 p:0026 s:0170 e:000169 METHOD /home/jaruga/git/ruby/ruby/test/ruby/test_gc_compact.rb:154
...
c:0001 p:0000 s:0003 E:001550 (none) [FINISH]
...

-- C level backtrace information -------------------------------------------
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_vm_bugreport+0x1b4) [0x7441be9c78f4] vm_dump.c:759
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_bug_without_die+0x9c) [0x7441be740dec] error.c:777
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(die+0x0) [0x7441be6807dc] error.c:785
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_bug) error.c:787
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(unlock_page_body+0x10) [0x7441be771e80] gc.c:4889
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(gc_fill_swept_page) gc.c:5184
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(gc_page_sweep) gc.c:5392
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(gc_sweep_step) gc.c:5562
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(gc_sweep_rest+0x24) [0x7441be77208c] gc.c:5619
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(gc_sweep) gc.c:5737
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(gc_marks+0x15c) [0x7441be778d08] gc.c:8024
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(gc_start) gc.c:8854
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_multi_ractor_p+0x0) [0x7441be77aa38] gc.c:8742
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_vm_lock_leave) vm_sync.h:92
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(garbage_collect) gc.c:8744
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(gc_start_internal) gc.c:9086
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(gc_compact) gc.c:10002
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(builtin_invoker0+0x24) [0x7441be988d34] vm_insnhelper.c:5429
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_exec_core+0x1914) [0x7441be9a8b14] vm_insnhelper.c:5569
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_vm_exec+0x14c) [0x7441be9acfdc] vm.c:2169
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_yield+0x288) [0x7441be9b23c8] vm.c:1260
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_ary_collect+0x74) [0x7441be68ca24] array.c:3646
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(ractor_safe_call_cfunc_0+0x24) [0x7441be9885b4] vm_insnhelper.c:2760
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_cfunc_with_frame+0x140) [0x7441be993d30] vm_insnhelper.c:2943
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_sendish+0x364) [0x7441be9a2ad4] vm_insnhelper.c:4516
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_exec_core+0x294) [0x7441be9a7494] insns.def:754
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_vm_exec+0x14c) [0x7441be9acfdc] vm.c:2169
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_yield+0x288) [0x7441be9b23c8] vm.c:1260
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_ary_each+0x54) [0x7441be683844] array.c:2534
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(ractor_safe_call_cfunc_0+0x24) [0x7441be9885b4] vm_insnhelper.c:2760
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_cfunc_with_frame+0x140) [0x7441be993d30] vm_insnhelper.c:2943
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_method_each_type+0xc0) [0x7441be9ae6d0] vm_insnhelper.c:3433
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_method+0xdc) [0x7441be9aeeec] vm_insnhelper.c:3537
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_method_each_type+0x510) [0x7441be9aeb20] vm_insnhelper.c:3412
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_method+0xdc) [0x7441be9aeeec] vm_insnhelper.c:3537
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_sendish+0x364) [0x7441be9a2ad4] vm_insnhelper.c:4516
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_exec_core+0x294) [0x7441be9a7494] insns.def:754
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_vm_exec+0x14c) [0x7441be9acfdc] vm.c:2169
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_yield+0x288) [0x7441be9b23c8] vm.c:1260
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_ary_each+0x54) [0x7441be683844] array.c:2534
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(ractor_safe_call_cfunc_0+0x24) [0x7441be9885b4] vm_insnhelper.c:2760
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_cfunc_with_frame+0x140) [0x7441be993d30] vm_insnhelper.c:2943
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_method_each_type+0xc0) [0x7441be9ae6d0] vm_insnhelper.c:3433
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_method+0xdc) [0x7441be9aeeec] vm_insnhelper.c:3537
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_method_each_type+0x510) [0x7441be9aeb20] vm_insnhelper.c:3412
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_method+0xdc) [0x7441be9aeeec] vm_insnhelper.c:3537
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_sendish+0x364) [0x7441be9a2ad4] vm_insnhelper.c:4516
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_exec_core+0x294) [0x7441be9a7494] insns.def:754
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_vm_exec+0x14c) [0x7441be9acfdc] vm.c:2169
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_iseq_eval+0x190) [0x7441be9b0bf0] vm.c:2406
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(require_internal+0x998) [0x7441be7cc8c8] load.c:594
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_require_string+0x44) [0x7441be7cd8f4] load.c:1142
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_f_require_relative+0x48) [0x7441be7cd9e8] load.c:857
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(ractor_safe_call_cfunc_1+0x28) [0x7441be988608] vm_insnhelper.c:2767
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_cfunc_with_frame+0x140) [0x7441be993d30] vm_insnhelper.c:2943
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_method_each_type+0xc0) [0x7441be9ae6d0] vm_insnhelper.c:3433
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_call_method+0xdc) [0x7441be9aeeec] vm_insnhelper.c:3537
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(vm_exec_core+0x1aac) [0x7441be9a8cac] vm_insnhelper.c:4516
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_vm_exec+0x14c) [0x7441be9acfdc] vm.c:2169
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_iseq_eval_main+0xf0) [0x7441be9b0d50] vm.c:2417
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(rb_ec_exec_node+0xb8) [0x7441be74a218] eval.c:317
/home/jaruga/git/ruby/ruby/libruby.so.3.1.0(ruby_run_node+0x7c) [0x7441be74e94c] eval.c:375
/home/jaruga/git/ruby/ruby/ruby(main+0x90) [0xa1b10ce0bb0] ./main.c:47
...
make: *** [uncommon.mk:802: yes-test-all] Aborted (core dumped)
```

```
$ make test-all TESTOPTS="-n test_compact_count" TESTS=test/ruby/test_gc_compact.rb
...
# Running tests:

[1/1] TestGCCompact#test_compact_count<internal:gc>:213: [BUG] Couldn't protect page 0x00000f8747228000
ruby 3.1.0dev (2021-05-19T05:24:01Z master adcbae8d49) [powerpc64le-linux]

-- Control frame information -----------------------------------------------
c:0031 p:0003 s:0174 e:000173 METHOD <internal:gc>:213
<internal:gc>:213: [BUG] Couldn't unprotect page 0x00000f8747234000
ruby 3.1.0dev (2021-05-19T05:24:01Z master adcbae8d49) [powerpc64le-linux]

-- Control frame information -----------------------------------------------
c:0031 p:0003 s:0174 e:000173 METHOD <internal:gc>:213
<internal:gc>:213: [BUG] Segmentation fault at 0x00000f8747236360
ruby 3.1.0dev (2021-05-19T05:24:01Z master adcbae8d49) [powerpc64le-linux]

-- Control frame information -----------------------------------------------
c:0031 p:0003 s:0174 e:000173 METHOD <internal:gc>:213
make: *** [uncommon.mk:802: yes-test-all] Segmentation fault (core dumped)
```



---Files--------------------------------
check.log (1.14 MB)


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