Hello, kernel test robot noticed "WARNING:suspicious_RCU_usage" on: commit: 8536fe0dad4ce46984d207cd53583e7c36bc94b1 ("[PATCH 2/2] mm: mempolicy: Interleave policy for tiered memory nodes") url: https://github.com/intel-lab-lkp/linux/commits/Ravi-Jonnalagadda/memory-tier-Introduce-sysfs-for-tier-interleave-weights/20230927-175208 base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git 612f769edd06a6e42f7cd72425488e68ddaeef0a patch link: https://lore.kernel.org/all/20230927095002.10245-3-ravis.opensrc@xxxxxxxxxx/ patch subject: [PATCH 2/2] mm: mempolicy: Interleave policy for tiered memory nodes in testcase: boot compiler: gcc-12 test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G (please refer to attached dmesg/kmsg for entire log/backtrace) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-lkp/202310210005.51e08d62-oliver.sang@xxxxxxxxx [ 3.474923][ T0] WARNING: suspicious RCU usage [ 3.476322][ T0] 6.6.0-rc1-00038-g8536fe0dad4c #2 Not tainted [ 3.478100][ T0] ----------------------------- [ 3.480319][ T0] mm/memory-tiers.c:258 suspicious rcu_dereference_check() usage! [ 3.482562][ T0] [ 3.482562][ T0] other info that might help us debug this: [ 3.482562][ T0] [ 3.484325][ T0] [ 3.484325][ T0] rcu_scheduler_active = 1, debug_locks = 1 [ 3.488321][ T0] no locks held by swapper/0/0. [ 3.489732][ T0] [ 3.489732][ T0] stack backtrace: [ 3.491424][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.6.0-rc1-00038-g8536fe0dad4c #2 [ 3.492304][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 3.492304][ T0] Call Trace: [ 3.492304][ T0] <TASK> [ 3.492304][ T0] dump_stack_lvl (kbuild/src/rand-x86_64-3/lib/dump_stack.c:107) [ 3.492304][ T0] lockdep_rcu_suspicious (kbuild/src/rand-x86_64-3/include/linux/context_tracking.h:153 kbuild/src/rand-x86_64-3/kernel/locking/lockdep.c:6712) [ 3.492304][ T0] node_get_memory_tier (kbuild/src/rand-x86_64-3/mm/memory-tiers.c:258 (discriminator 11)) [ 3.492304][ T0] node_interleave_weight (kbuild/src/rand-x86_64-3/mm/mempolicy.c:1921) [ 3.492304][ T0] ? __orc_find (kbuild/src/rand-x86_64-3/arch/x86/kernel/unwind_orc.c:110) [ 3.492304][ T0] ? secondary_startup_64_no_verify (kbuild/src/rand-x86_64-3/arch/x86/kernel/head_64.S:433) [ 3.492304][ T0] ? orc_find (kbuild/src/rand-x86_64-3/arch/x86/kernel/unwind_orc.c:242) [ 3.492304][ T0] ? secondary_startup_64_no_verify (kbuild/src/rand-x86_64-3/arch/x86/kernel/head_64.S:433) [ 3.492304][ T0] ? secondary_startup_64_no_verify (kbuild/src/rand-x86_64-3/arch/x86/kernel/head_64.S:433) [ 3.492304][ T0] ? unwind_next_frame (kbuild/src/rand-x86_64-3/arch/x86/kernel/unwind_orc.c:682) [ 3.492304][ T0] interleave_nodes (kbuild/src/rand-x86_64-3/mm/mempolicy.c:1969) [ 3.492304][ T0] mempolicy_slab_node (kbuild/src/rand-x86_64-3/mm/mempolicy.c:2007) [ 3.492304][ T0] __slab_alloc_node+0x195/0x320 [ 3.492304][ T0] slab_alloc_node+0x67/0x160 [ 3.492304][ T0] kmem_cache_alloc_node (kbuild/src/rand-x86_64-3/mm/slub.c:3525) [ 3.492304][ T0] dup_task_struct (kbuild/src/rand-x86_64-3/kernel/fork.c:173 kbuild/src/rand-x86_64-3/kernel/fork.c:1110) [ 3.492304][ T0] copy_process (kbuild/src/rand-x86_64-3/kernel/fork.c:2327) [ 3.492304][ T0] ? kvm_sched_clock_read (kbuild/src/rand-x86_64-3/arch/x86/kernel/kvmclock.c:91) [ 3.492304][ T0] kernel_clone (kbuild/src/rand-x86_64-3/include/linux/random.h:26 kbuild/src/rand-x86_64-3/kernel/fork.c:2910) [ 3.492304][ T0] ? rest_init (kbuild/src/rand-x86_64-3/init/main.c:1429) [ 3.492304][ T0] user_mode_thread (kbuild/src/rand-x86_64-3/kernel/fork.c:2988) [ 3.492304][ T0] ? rest_init (kbuild/src/rand-x86_64-3/init/main.c:1429) [ 3.492304][ T0] rest_init (kbuild/src/rand-x86_64-3/init/main.c:691) [ 3.492304][ T0] ? acpi_enable_subsystem (kbuild/src/rand-x86_64-3/drivers/acpi/acpica/utxfinit.c:192) [ 3.492304][ T0] arch_call_rest_init+0xf/0x20 [ 3.492304][ T0] start_kernel (kbuild/src/rand-x86_64-3/init/main.c:1019 (discriminator 1)) [ 3.492304][ T0] x86_64_start_reservations (kbuild/src/rand-x86_64-3/arch/x86/kernel/head64.c:544) [ 3.492304][ T0] x86_64_start_kernel (kbuild/src/rand-x86_64-3/arch/x86/kernel/head64.c:486 (discriminator 17)) [ 3.492304][ T0] secondary_startup_64_no_verify (kbuild/src/rand-x86_64-3/arch/x86/kernel/head_64.S:433) [ 3.492304][ T0] </TASK> The kernel config and materials to reproduce are available at: https://download.01.org/0day-ci/archive/20231021/202310210005.51e08d62-oliver.sang@xxxxxxxxx -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki