Process stuck in unkillable state if operating with inotify

From: Oleg Nauman <oleg.nauman_at_gmail.com>
Date: Thu, 10 Jul 2025 07:06:52 UTC
I noticed that some processes consume 100% of CPU and unkillable even
with kill -9
System info: CURRENT 17f0f75308f2 ( Jul 8 ) amd64

The only meaningful info I was able to collect it is output of
procstat -kk, so two examples of call stack for such type of
processes:

  PID    TID COMM                TDNAME              KSTACK
 3192 100876 polkitd             -
_vn_lock_fallback+0x9e _vn_lock+0x8a vfs_lookup+0x122 namei+0x26d
vn_inotify_add_watch+0x1b9 VOP_INOTIFY_ADD_WATCH+0x3a
kern_inotify_add_watch+0x2be amd64_syscall+0x118
fast_syscall_common+0xf8
 3192 100889 polkitd             gmain               mi_switch+0xbc
sleepq_catch_signals+0x27d sleepq_wait_sig+0x9 _cv_wait_sig+0xf5
seltdwait+0x9a kern_poll_kfds+0x517 kern_poll+0x107 sys_ppoll+0x70
amd64_syscall+0x118 fast_syscall_common+0xf8

and

  PID    TID COMM                TDNAME              KSTACK
58129 100829 packagekitd         -                   ffs_lock+0x7d
_vn_lock_fallback+0x9e _vn_lock+0x8a vfs_lookup+0x122 namei+0x26d
vn_inotify_add_watch+0x1b9 VOP_INOTIFY_ADD_WATCH+0x3a
kern_inotify_add_watch+0x2be amd64_syscall+0x118
fast_syscall_common+0xf8
58129 103627 packagekitd         pool-spawner        mi_switch+0xbc
sleepq_catch_signals+0x27d sleepq_wait_sig+0x9 _sleep+0x197
umtxq_sleep+0x2c1 do_wait+0x258 __umtx_op_wait_uint_private+0x54
sys__umtx_op+0x7e amd64_syscall+0x118 fast_syscall_common+0xf8
58129 103628 packagekitd         gmain               mi_switch+0xbc
sleepq_catch_signals+0x27d sleepq_wait_sig+0x9 _cv_wait_sig+0xf5
seltdwait+0x9a kern_poll_kfds+0x517 kern_poll+0x107 sys_ppoll+0x70
amd64_syscall+0x118 fast_syscall_common+0xf8
58129 103629 packagekitd         gdbus               mi_switch+0xbc
sleepq_catch_signals+0x27d sleepq_wait_sig+0x9 _cv_wait_sig+0xf5
seltdwait+0x9a kern_poll_kfds+0x517 kern_poll+0x107 sys_ppoll+0x70
amd64_syscall+0x118 fast_syscall_common+0xf8

Thank you