Hi all, On 6.14-rc1, I found that creating a lot of files in tmpfs then deleting them reliably hangs when tmpfs is mounted with huge=within_size, and it is swapped out to zram (zstd/zsmalloc/no backing dev). I bisected this to acd7ccb284b "mm: shmem: add large folio support for tmpfs". When the issue occurs, rm uses 100% CPU, cannot be killed, and has no output in /proc/pid/stack or wchan. Eventually, an RCU stall is detected: rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-11): P25160 rcu: (detected by 10, t=2102 jiffies, g=532677, q=4997 ncpus=12) task:rm state:R running task stack:0 pid:25160 tgid:25160 ppid:24309 task_flags:0x400000 flags:0x00004004 Call Trace: <TASK> ? __schedule+0x388/0x1000 ? kmem_cache_free.part.0+0x23d/0x280 ? sysvec_apic_timer_interrupt+0xa/0x80 ? asm_sysvec_apic_timer_interrupt+0x16/0x20 ? xas_load+0x12/0xc0 ? xas_load+0x8/0xc0 ? xas_find+0x144/0x190 ? find_lock_entries+0x75/0x260 ? shmem_undo_range+0xe6/0x5f0 ? shmem_evict_inode+0xe4/0x230 ? mtree_erase+0x7e/0xe0 ? inode_set_ctime_current+0x2e/0x1f0 ? evict+0xe9/0x260 ? _atomic_dec_and_lock+0x31/0x50 ? do_unlinkat+0x270/0x2b0 ? __x64_sys_unlinkat+0x30/0x50 ? do_syscall_64+0x37/0xe0 ? entry_SYSCALL_64_after_hwframe+0x50/0x58 </TASK> Let me know what information is needed to further troubleshoot this issue. Thanks, Alex.
