just ran the new Dhrystone test on one of my machines post-boot (using `echo y > /sys/module/test_dhry/parameters/run`) and: ``` BUG: using smp_processor_id() in preemptible [00000000] code: bash/1903 caller is dhry_benchmark+0x39/0x90 CPU: 5 PID: 1903 Comm: bash Not tainted 6.3.0-rc1 #13 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./B450 Pro4 R2.0, BIOS H4.84 04/08/2021 Call Trace: <TASK> dump_stack_lvl+0x32/0x50 check_preemption_disabled+0xe6/0x100 dhry_benchmark+0x39/0x90 dhry_run_set+0x33/0x40 param_attr_store+0x98/0x100 module_attr_store+0x18/0x30 kernfs_fop_write_iter+0x14e/0x220 vfs_write+0x29a/0x460 ksys_write+0x74/0x100 do_syscall_64+0x3a/0xc0 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7f5eec252190 Code: 40 00 48 8b 15 71 9c 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 51 24 0e 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89 RSP: 002b:00007ffc4b1dea68 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f5eec252190 RDX: 0000000000000002 RSI: 000055d3c05b4540 RDI: 0000000000000001 RBP: 000055d3c05b4540 R08: 00007f5eec32d3d0 R09: 00007f5eec32d3d0 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 R13: 00007f5eec32d760 R14: 0000000000000002 R15: 00007f5eec3289e0 </TASK> CPU5: Dhrystones per Second: 34361907 (19557 DMIPS) ``` Test completes fine (with a credible result) and the machine keeps running. Running it through decode_stacktrache.sh yields: ``` $ scripts/decode_stacktrace.sh vmlinux < log BUG: using smp_processor_id() in preemptible [00000000] code: bash/1903 caller is dhry_benchmark (lib/dhry_run.c:49) CPU: 5 PID: 1903 Comm: bash Not tainted 6.3.0-rc1 #13 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./B450 Pro4 R2.0, BIOS H4.84 04/08/2021 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1)) check_preemption_disabled (./arch/x86/include/asm/preempt.h:85 lib/smp_processor_id.c:53) dhry_benchmark (lib/dhry_run.c:49) dhry_run_set (lib/dhry_run.c:70) param_attr_store (kernel/params.c:586) module_attr_store (kernel/params.c:922) kernfs_fop_write_iter (fs/kernfs/file.c:338) vfs_write (fs/read_write.c:492 fs/read_write.c:584) ksys_write (fs/read_write.c:638) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) RIP: 0033:0x7f5eec252190 Code: 40 00 48 8b 15 71 9c 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 51 24 0e Code starting with the faulting instruction =========================================== 0: 40 00 48 8b rex add %cl,-0x75(%rax) 4: 15 71 9c 0d 00 adc $0xd9c71,%eax 9: f7 d8 neg %eax b: 64 89 02 mov %eax,%fs:(%rdx) e: 48 c7 c0 ff ff ff ff mov $0xffffffffffffffff,%rax 15: eb b7 jmp 0xffffffffffffffce 17: 0f 1f 00 nopl (%rax) 1a: 80 .byte 0x80 1b: 3d .byte 0x3d 1c: 51 push %rcx 1d: 24 0e and $0xe,%al 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89 RSP: 002b:00007ffc4b1dea68 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f5eec252190 RDX: 0000000000000002 RSI: 000055d3c05b4540 RDI: 0000000000000001 RBP: 000055d3c05b4540 R08: 00007f5eec32d3d0 R09: 00007f5eec32d3d0 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 R13: 00007f5eec32d760 R14: 0000000000000002 R15: 00007f5eec3289e0 </TASK> CPU5: Dhrystones per Second: 34361907 (19557 DMIPS) ```
Almost no one is subscribed to Other Other so your best bet will be to bisect: https://docs.kernel.org/admin-guide/bug-bisect.html
There isn't anything to bisect here. All the code was introduced in one commit, d5528cc16893f1f64b07936b1e88aa023128debb. Without that commit, there is no test to run.
Created attachment 303936 [details] Patch to fix BUG on run of Dhrystone benchmark This patch fixes the issue for me, but I don't know if it is the right approach.