Greeting, FYI, we noticed the following commit (built with gcc-9): commit: 9720a64438d901dad40d4791daf017507fe67f51 ("sched: Report local wake up on resched blind zone within idle loop") url: https://github.com/0day-ci/linux/commits/Frederic-Weisbecker/rcu-sched-Fix-ignored-rescheduling-after-rcu_eqs_enter-v3/20210109-100950 in testcase: boot on test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 8G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +--------------------------------------------------------------------+------------+------------+ | | 13b5aef705 | 9720a64438 | +--------------------------------------------------------------------+------------+------------+ | boot_successes | 16 | 0 | | boot_failures | 0 | 18 | | WARNING:at_kernel/sched/core.c:#sched_resched_local_assert_allowed | 0 | 18 | | EIP:sched_resched_local_assert_allowed | 0 | 18 | | EIP:default_idle | 0 | 18 | +--------------------------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 0.278654] WARNING: CPU: 1 PID: 0 at kernel/sched/core.c:628 sched_resched_local_assert_allowed (kbuild/src/consumer/kernel/sched/core.c:628 (discriminator 13)) [ 0.278654] Modules linked in: [ 0.278654] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.11.0-rc2-00006-g9720a64438d9 #2 [ 0.278654] EIP: sched_resched_local_assert_allowed (kbuild/src/consumer/kernel/sched/core.c:628 (discriminator 13)) [ 0.278654] Code: 00 00 00 b8 98 76 e3 97 ff 05 a4 1d ee 97 c6 05 76 31 e2 97 01 e8 b2 38 92 ff ff 05 90 1d ee 97 68 39 b2 97 97 e8 f7 16 ff ff <0f> 0b 6a 01 31 c9 ba 01 00 00 00 b8 80 76 e3 97 e8 8d 38 92 ff 83 All code ======== 0: 00 00 add %al,(%rax) 2: 00 b8 98 76 e3 97 add %bh,-0x681c8968(%rax) 8: ff 05 a4 1d ee 97 incl -0x6811e25c(%rip) # 0xffffffff97ee1db2 e: c6 05 76 31 e2 97 01 movb $0x1,-0x681dce8a(%rip) # 0xffffffff97e2318b 15: e8 b2 38 92 ff callq 0xffffffffff9238cc 1a: ff 05 90 1d ee 97 incl -0x6811e270(%rip) # 0xffffffff97ee1db0 20: 68 39 b2 97 97 pushq $0xffffffff9797b239 25: e8 f7 16 ff ff callq 0xffffffffffff1721 2a:* 0f 0b ud2 <-- trapping instruction 2c: 6a 01 pushq $0x1 2e: 31 c9 xor %ecx,%ecx 30: ba 01 00 00 00 mov $0x1,%edx 35: b8 80 76 e3 97 mov $0x97e37680,%eax 3a: e8 8d 38 92 ff callq 0xffffffffff9238cc 3f: 83 .byte 0x83 Code starting with the faulting instruction =========================================== 0: 0f 0b ud2 2: 6a 01 pushq $0x1 4: 31 c9 xor %ecx,%ecx 6: ba 01 00 00 00 mov $0x1,%edx b: b8 80 76 e3 97 mov $0x97e37680,%eax 10: e8 8d 38 92 ff callq 0xffffffffff9238a2 15: 83 .byte 0x83 [ 0.278654] EAX: 0000002a EBX: 00000001 ECX: 00000000 EDX: 00000000 [ 0.278654] ESI: d95f4f00 EDI: 80540000 EBP: 8054bdc0 ESP: 8054bdb4 [ 0.278654] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00210086 [ 0.278654] CR0: 80050033 CR2: 00000000 CR3: 18370000 CR4: 000406b0 [ 0.278654] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 0.278654] DR6: fffe0ff0 DR7: 00000400 [ 0.278654] Call Trace: [ 0.278654] resched_curr (kbuild/src/consumer/kernel/sched/core.c:655 (discriminator 24)) [ 0.278654] check_preempt_curr (kbuild/src/consumer/kernel/sched/core.c:1750 (discriminator 4)) [ 0.278654] ttwu_do_wakeup (kbuild/src/consumer/kernel/sched/core.c:2976) [ 0.278654] ttwu_do_activate (kbuild/src/consumer/kernel/sched/core.c:3027) [ 0.278654] try_to_wake_up (kbuild/src/consumer/kernel/sched/core.c:3216 kbuild/src/consumer/kernel/sched/core.c:3493) [ 0.278654] ? sysvec_call_function (kbuild/src/consumer/arch/x86/kernel/smp.c:243) [ 0.278654] wake_up_process (kbuild/src/consumer/kernel/sched/core.c:3564) [ 0.278654] wakeup_softirqd (kbuild/src/consumer/kernel/softirq.c:77 (discriminator 3)) [ 0.278654] raise_softirq_irqoff (kbuild/src/consumer/kernel/softirq.c:467 (discriminator 1)) [ 0.278654] raise_softirq (kbuild/src/consumer/kernel/softirq.c:476 (discriminator 7)) [ 0.278654] invoke_rcu_core (kbuild/src/consumer/kernel/rcu/tree.c:2793 (discriminator 4)) [ 0.278654] rcu_cleanup_after_idle (kbuild/src/consumer/kernel/rcu/tree_plugin.h:1434 (discriminator 1)) [ 0.278654] rcu_nmi_enter (kbuild/src/consumer/kernel/rcu/tree.c:1033 (discriminator 1)) [ 0.278654] rcu_irq_enter (kbuild/src/consumer/kernel/rcu/tree.c:1087 (discriminator 49)) [ 0.278654] irqentry_enter (kbuild/src/consumer/kernel/entry/common.c:369 (discriminator 1)) [ 0.278654] sysvec_call_function_single (kbuild/src/consumer/arch/x86/kernel/smp.c:243) [ 0.278654] handle_exception (kbuild/src/consumer/arch/x86/entry/entry_32.S:1179) [ 0.278654] EIP: default_idle (kbuild/src/consumer/arch/x86/kernel/process.c:689) [ 0.278654] Code: eb 97 fb b8 15 00 00 00 64 8b 15 5c b8 21 98 e8 1b 5a 7e ff 8d 65 f8 5b 5e 5d c3 66 66 66 66 90 55 89 e5 e8 9a 5a 7e ff fb f4 <5d> c3 66 66 66 66 90 89 c2 55 a1 e0 ae 37 98 0f b6 52 09 64 8b 0d All code ======== 0: eb 97 jmp 0xffffffffffffff99 2: fb sti 3: b8 15 00 00 00 mov $0x15,%eax 8: 64 8b 15 5c b8 21 98 mov %fs:-0x67de47a4(%rip),%edx # 0xffffffff9821b86b f: e8 1b 5a 7e ff callq 0xffffffffff7e5a2f 14: 8d 65 f8 lea -0x8(%rbp),%esp 17: 5b pop %rbx 18: 5e pop %rsi 19: 5d pop %rbp 1a: c3 retq 1b: 66 66 66 66 90 data16 data16 data16 xchg %ax,%ax 20: 55 push %rbp 21: 89 e5 mov %esp,%ebp 23: e8 9a 5a 7e ff callq 0xffffffffff7e5ac2 28: fb sti 29: f4 hlt 2a:* 5d pop %rbp <-- trapping instruction 2b: c3 retq 2c: 66 66 66 66 90 data16 data16 data16 xchg %ax,%ax 31: 89 c2 mov %eax,%edx 33: 55 push %rbp 34: a1 e0 ae 37 98 0f b6 movabs 0x952b60f9837aee0,%eax 3b: 52 09 3d: 64 fs 3e: 8b .byte 0x8b 3f: 0d .byte 0xd Code starting with the faulting instruction =========================================== 0: 5d pop %rbp 1: c3 retq 2: 66 66 66 66 90 data16 data16 data16 xchg %ax,%ax 7: 89 c2 mov %eax,%edx 9: 55 push %rbp a: a1 e0 ae 37 98 0f b6 movabs 0x952b60f9837aee0,%eax 11: 52 09 13: 64 fs 14: 8b .byte 0x8b 15: 0d .byte 0xd [ 0.278654] EAX: 00000000 EBX: 00000000 ECX: 00000001 EDX: 00000000 [ 0.278654] ESI: 80540000 EDI: 00000000 EBP: 8054bf54 ESP: 8054bf54 [ 0.278654] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00200206 [ 0.278654] ? rcu_dump_cpu_stacks (kbuild/src/consumer/kernel/rcu/tree_stall.h:333 (discriminator 1)) [ 0.278654] ? sysvec_call_function (kbuild/src/consumer/arch/x86/kernel/smp.c:243) [ 0.278654] ? default_idle (kbuild/src/consumer/arch/x86/kernel/process.c:689) [ 0.278654] arch_cpu_idle (kbuild/src/consumer/arch/x86/kernel/process.c:681) [ 0.278654] default_idle_call (kbuild/src/consumer/arch/x86/include/asm/irqflags.h:49 (discriminator 2) kbuild/src/consumer/arch/x86/include/asm/irqflags.h:89 (discriminator 2) kbuild/src/consumer/kernel/sched/idle.c:121 (discriminator 2)) [ 0.278654] cpuidle_idle_call (kbuild/src/consumer/kernel/sched/idle.c:200 (discriminator 1)) [ 0.278654] do_idle (kbuild/src/consumer/kernel/sched/idle.c:307) [ 0.278654] cpu_startup_entry (kbuild/src/consumer/kernel/sched/idle.c:401 (discriminator 1)) [ 0.278654] start_secondary (kbuild/src/consumer/arch/x86/kernel/smpboot.c:272) [ 0.278654] startup_32_smp (kbuild/src/consumer/arch/x86/kernel/head_32.S:328) [ 0.278654] irq event stamp: 1280 [ 0.278654] hardirqs last enabled at (1279): default_idle_call (kbuild/src/consumer/kernel/sched/idle.c:96 (discriminator 2)) [ 0.278654] hardirqs last disabled at (1280): sysvec_call_function_single (kbuild/src/consumer/arch/x86/kernel/smp.c:243) [ 0.278654] softirqs last enabled at (1246): __do_softirq (kbuild/src/consumer/kernel/softirq.c:371) [ 0.278654] softirqs last disabled at (1201): do_softirq_own_stack (kbuild/src/consumer/arch/x86/kernel/irq_32.c:59 kbuild/src/consumer/arch/x86/kernel/irq_32.c:148) [ 0.278654] ---[ end trace f16ac7c94443e620 ]--- [ 0.318955] ACPI: Added _OSI(Module Device) [ 0.319271] ACPI: Added _OSI(Processor Device) [ 0.319553] ACPI: Added _OSI(3.0 _SCP Extensions) [ 0.319845] ACPI: Added _OSI(Processor Aggregator Device) [ 0.320179] ACPI: Added _OSI(Linux-Dell-Video) [ 0.320456] ACPI: Added _OSI(Linux-Lenovo-NV-HDMI-Audio) [ 0.320797] ACPI: Added _OSI(Linux-HPI-Hybrid-Graphics) [ 0.325521] ACPI: 1 ACPI AML tables successfully acquired and loaded [ 0.329232] ACPI: Interpreter enabled [ 0.329527] ACPI: (supports S0 S3 S5) [ 0.329768] ACPI: Using IOAPIC for interrupt routing [ 0.330126] PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug [ 0.331290] ACPI: Enabled 2 GPEs in block 00 to 0F [ 0.349832] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff]) [ 0.350277] acpi PNP0A03:00: _OSC: OS supports [ASPM ClockPM Segments HPX-Type3] [ 0.350816] acpi PNP0A03:00: fail to add MMCONFIG information, can't access extended PCI configuration space under this bridge. [ 0.351562] PCI host bridge to bus 0000:00 [ 0.351831] pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7 window] [ 0.352249] pci_bus 0000:00: root bus resource [io 0x0d00-0xffff window] [ 0.352666] pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff window] [ 0.353125] pci_bus 0000:00: root bus resource [mem 0xc0000000-0xfebfffff window] [ 0.353591] pci_bus 0000:00: root bus resource [mem 0x240000000-0x2bfffffff window] [ 0.354059] pci_bus 0000:00: root bus resource [bus 00-ff] [ 0.354465] pci 0000:00:00.0: [8086:1237] type 00 class 0x060000 [ 0.355655] pci 0000:00:01.0: [8086:7000] type 00 class 0x060100 [ 0.356963] pci 0000:00:01.1: [8086:7010] type 00 class 0x010180 [ 0.359846] pci 0000:00:01.1: reg 0x20: [io 0xc040-0xc04f] [ 0.361169] pci 0000:00:01.1: legacy IDE quirk: reg 0x10: [io 0x01f0-0x01f7] [ 0.361316] pci 0000:00:01.1: legacy IDE quirk: reg 0x14: [io 0x03f6] [ 0.361716] pci 0000:00:01.1: legacy IDE quirk: reg 0x18: [io 0x0170-0x0177] [ 0.362151] pci 0000:00:01.1: legacy IDE quirk: reg 0x1c: [io 0x0376] [ 0.363135] pci 0000:00:01.3: [8086:7113] type 00 class 0x068000 [ 0.363727] pci 0000:00:01.3: quirk: [io 0x0600-0x063f] claimed by PIIX4 ACPI To reproduce: # build kernel cd linux cp config-5.11.0-rc2-00006-g9720a64438d9 .config make HOSTCC=gcc-9 CC=gcc-9 ARCH=i386 olddefconfig prepare modules_prepare bzImage git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k job-script # job-script is attached in this email Thanks, Oliver Sang