rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=119713, q=208) rcu: All QSes seen, last rcu_preempt kthread activity 10454 (4295029459-4295019005), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10454 jiffies! g119713 f0x2 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:28944 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 2289 Comm: syz-executor.3 Not tainted 5.16.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline] check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2597 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:folio_flags.constprop.0+0x2/0x70 include/linux/page-flags.h:259 Code: ff e9 d6 ed ff ff 48 8b 7c 24 38 e8 68 0a a4 ff e9 b1 ed ff ff 48 8b 7c 24 40 e8 d9 09 a4 ff e9 8a ed ff ff cc cc cc cc 41 54 <49> 89 fc 53 e8 c5 c7 5d ff 49 8d 7c 24 08 48 b8 00 00 00 00 00 fc RSP: 0018:ffffc90002927180 EFLAGS: 00000282 RAX: ffffea0000b52080 RBX: 000000000000001d RCX: ffffc90002927058 RDX: 1ffff1100a4c816a RSI: 0000000000000000 RDI: ffffea0000b52080 RBP: ffffea0000b52080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 000000000000000c R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 folio_test_locked include/linux/page-flags.h:417 [inline] __readahead_folio include/linux/pagemap.h:1069 [inline] readahead_page include/linux/pagemap.h:1086 [inline] ext4_mpage_readpages+0x391/0x1db0 fs/ext4/readpage.c:255 ext4_readahead+0x102/0x140 fs/ext4/inode.c:3199 read_pages+0x1e4/0xfa0 mm/readahead.c:129 page_cache_ra_unbounded+0x64b/0x940 mm/readahead.c:238 do_page_cache_ra mm/readahead.c:268 [inline] ondemand_readahead+0x594/0x1090 mm/readahead.c:551 page_cache_async_ra mm/readahead.c:608 [inline] page_cache_async_ra+0x2e1/0x3f0 mm/readahead.c:583 page_cache_async_readahead include/linux/pagemap.h:1052 [inline] filemap_readahead mm/filemap.c:2531 [inline] filemap_get_pages+0x6f1/0x1be0 mm/filemap.c:2572 filemap_read+0x315/0xeb0 mm/filemap.c:2642 generic_file_read_iter+0x3b6/0x5a0 mm/filemap.c:2792 ext4_file_read_iter+0x1d4/0x5d0 fs/ext4/file.c:130 call_read_iter include/linux/fs.h:2156 [inline] generic_file_splice_read+0x453/0x6d0 fs/splice.c:311 do_splice_to+0x1bf/0x250 fs/splice.c:796 splice_direct_to_actor+0x2c2/0x8c0 fs/splice.c:870 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xaf2/0x1250 fs/read_write.c:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1296 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7efd588eae99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007efd57260168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007efd589fdf60 RCX: 00007efd588eae99 RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000005 RBP: 00007efd58944ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffa R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc14ab8c3f R14: 00007efd57260300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: e9 d6 ed ff ff jmpq 0xffffeddb 5: 48 8b 7c 24 38 mov 0x38(%rsp),%rdi a: e8 68 0a a4 ff callq 0xffa40a77 f: e9 b1 ed ff ff jmpq 0xffffedc5 14: 48 8b 7c 24 40 mov 0x40(%rsp),%rdi 19: e8 d9 09 a4 ff callq 0xffa409f7 1e: e9 8a ed ff ff jmpq 0xffffedad 23: cc int3 24: cc int3 25: cc int3 26: cc int3 27: 41 54 push %r12 * 29: 49 89 fc mov %rdi,%r12 <-- trapping instruction 2c: 53 push %rbx 2d: e8 c5 c7 5d ff callq 0xff5dc7f7 32: 49 8d 7c 24 08 lea 0x8(%r12),%rdi 37: 48 rex.W 38: b8 00 00 00 00 mov $0x0,%eax 3d: 00 fc add %bh,%ah