sched: RT throttling activated rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6487/2:b..l rcu: (detected by 0, t=10502 jiffies, g=15345, q=532 ncpus=2) task:syz.2.137 state:R running task stack:25768 pid:6487 ppid:5766 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_is_held_type+0x13e/0x190 kernel/locking/lockdep.c:5830 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90004bef668 EFLAGS: 00000206 RAX: f02ca96c7d324600 RBX: ffff8880278c8000 RCX: f02ca96c7d324600 RDX: ffff8880278c8000 RSI: ffffffff8aaace60 RDI: ffffffff8afc6f80 RBP: 0000000000000001 R08: ffff8880278c8000 R09: 0000000000000002 R10: 0000000000000003 R11: 0000000000000002 R12: 0000000000000001 R13: 0000000000000246 R14: ffffffff8cd2ff20 R15: ffff8880278c8b08 xa_entry include/linux/xarray.h:1216 [inline] xas_find+0x5b1/0xab0 lib/xarray.c:1267 next_uptodate_folio+0x33/0xae0 mm/filemap.c:3481 filemap_map_pages+0x228/0x1950 mm/filemap.c:3620 do_fault_around mm/memory.c:4595 [inline] do_read_fault mm/memory.c:4628 [inline] do_fault mm/memory.c:4775 [inline] do_pte_missing mm/memory.c:3689 [inline] handle_pte_fault mm/memory.c:5047 [inline] __handle_mm_fault mm/memory.c:5188 [inline] handle_mm_fault+0x379b/0x4920 mm/memory.c:5353 faultin_page mm/gup.c:868 [inline] __get_user_pages+0x5ea/0x1470 mm/gup.c:1167 populate_vma_page_range+0x2b6/0x370 mm/gup.c:1593 __mm_populate+0x24c/0x380 mm/gup.c:1696 mm_populate include/linux/mm.h:3383 [inline] vm_mmap_pgoff+0x2e7/0x400 mm/util.c:561 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f33f258f749 RSP: 002b:00007f33f3468038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f33f27e6090 RCX: 00007f33f258f749 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f33f2613f91 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f33f27e6128 R14: 00007f33f27e6090 R15: 00007ffca33b4d88 rcu: rcu_preempt kthread starved for 10350 jiffies! g15345 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:26760 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148 Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 23 bb 40 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56 RSP: 0000:ffffc90000187de0 EFLAGS: 000002c2 RAX: 06a4308b412f7400 RBX: ffffffff8161881b RCX: 06a4308b412f7400 RDX: 0000000000000001 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80 RBP: ffffc90000187f20 R08: ffff8880b8f36b2b R09: 1ffff110171e6d65 R10: dffffc0000000000 R11: ffffed10171e6d66 R12: ffffffff8e4a2128 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1100364e780 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c4b279dcc8 CR3: 000000002cefe000 CR4: 00000000003506e0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1eb/0x510 kernel/sched/idle.c:282 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380 start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323 secondary_startup_64_no_verify+0x179/0x17b