FYI, we noticed the below changes on https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf/core commit 7f47d8cc039f8746e0038fe05f1ddcb15a2e27f0 ("x86, tracing, perf: Add trace point for MSR accesses") +--------------------------------------------------+------------+------------+ | | bd2a634d9e | 7f47d8cc03 | +--------------------------------------------------+------------+------------+ | boot_successes | 10 | 2 | | boot_failures | 0 | 8 | | BUG:kernel_early-boot_hang | 0 | 2 | | INFO:suspicious_RCU_usage | 0 | 6 | | RCU_used_illegally_from_idle_CPU | 0 | 6 | | RCU_used_illegally_from_extended_quiescent_state | 0 | 6 | | invoked_oom-killer:gfp_mask=0x | 0 | 5 | | Mem-Info | 0 | 5 | | Out_of_memory:Kill_process | 0 | 5 | | backtrace:cpu_startup_entry | 0 | 4 | | backtrace:vfs_writev | 0 | 3 | | backtrace:SyS_writev | 0 | 3 | | backtrace:_do_fork | 0 | 1 | | backtrace:SyS_clone | 0 | 1 | | backtrace:vfs_write | 0 | 1 | | backtrace:SyS_write | 0 | 1 | +--------------------------------------------------+------------+------------+ [main] Added 32 filenames from /dev [ 45.280682] [ 45.281065] =============================== [ 45.281884] [ INFO: suspicious RCU usage. ] [ 45.282527] 4.4.0-rc2-00097-g7f47d8c #23 Not tainted [ 45.283253] ------------------------------- [ 45.284035] arch/x86/include/asm/msr-trace.h:47 suspicious rcu_dereference_check() usage! [ 45.285533] [ 45.285533] other info that might help us debug this: [ 45.285533] [ 45.286929] [ 45.286929] RCU used illegally from idle CPU! [ 45.286929] rcu_scheduler_active = 1, debug_locks = 0 [ 45.289836] RCU used illegally from extended quiescent state! [ 45.291309] no locks held by swapper/0/0. [ 45.292430] [ 45.292430] stack backtrace: [ 45.293441] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-rc2-00097-g7f47d8c #23 [ 45.294571] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 45.295898] 0000000000000000 ffff88009f403ed8 ffffffff8173cf5f ffffffff84019500 [ 45.298424] ffff88009f403f08 ffffffff81113775 0000000000000000 0000000000000000 [ 45.300879] ffffffff84004000 ffffffff84000000 ffff88009f403f38 ffffffff81772b19 [ 45.303367] Call Trace: [ 45.304171] [] dump_stack+0x4b/0x63 [ 45.305793] [] lockdep_rcu_suspicious+0xf7/0x100 [ 45.307352] [] do_trace_write_msr+0x9b/0xf4 [ 45.308856] [] native_write_msr_safe+0x2e/0x33 [ 45.310293] [] paravirt_write_msr+0xf/0x13 [ 45.311116] [] native_apic_msr_write+0x29/0x2b [ 45.311997] [] kvm_guest_apic_eoi_write+0x36/0x38 [ 45.312878] [] apic_eoi+0x18/0x1a [ 45.313856] [] smp_apic_timer_interrupt+0x1f/0x3e [ 45.314766] [] apic_timer_interrupt+0x87/0x90 [ 45.315605] [] ? native_safe_halt+0x6/0x8 [ 45.316571] [] default_idle+0x24/0x37 [ 45.317750] [] arch_cpu_idle+0xf/0x11 [ 45.318794] [] default_idle_call+0x28/0x2f [ 45.319610] [] cpu_startup_entry+0x17a/0x29a [ 45.321018] [] rest_init+0x13a/0x140 [ 45.322382] [] start_kernel+0x45e/0x46b [ 45.323443] [] ? early_idt_handler_array+0x120/0x120 [ 45.324386] [] x86_64_start_reservations+0x2a/0x2c [ 45.325363] [] x86_64_start_kernel+0x12d/0x13a [main] Added 107172 filenames from /proc [main] Added 25531 filenames from /sys [main] Enabled 9 fd providers. To reproduce: git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git cd lkp-tests bin/lkp install job.yaml # job file is attached in this email bin/lkp run job.yaml Thanks, Ying Huang