(kgdb) thread 219 [Switching to thread 219 (Thread 100242)]#0 sched_switch (td=0xfffff80079fd3a00, newtd=, flags=) at /usr/src/sys/kern/sched_ule.c:1956 1956 cpuid = PCPU_GET(cpuid); Current language: auto; currently minimal (kgdb) bt #0 sched_switch (td=0xfffff80079fd3a00, newtd=, flags=) at /usr/src/sys/kern/sched_ule.c:1956 #1 0xffffffff8097ea51 in mi_switch (flags=0, newtd=0x0) at /usr/src/sys/kern/kern_synch.c:473 #2 0xffffffff809c3312 in sleepq_switch (wchan=, pri=) at /usr/src/sys/kern/subr_sleepqueue.c:553 #3 0xffffffff809c3173 in sleepq_wait (wchan=0xffffffff81727738, pri=0) at /usr/src/sys/kern/subr_sleepqueue.c:632 #4 0xffffffff8097d5b3 in _sx_xlock_hard (sx=0xffffffff81727738, tid=18446735279663168000, opts=, file=, line=) at /usr/src/sys/kern/kern_sx.c:742 #5 0xffffffff8097ca66 in _sx_xlock (sx=0xffffffff81727738, opts=0, file=0xffffffff81067ba3 "/usr/src/sys/kern/kern_sysctl.c", line=1633) at sx.h:153 #6 0xffffffff8098109c in userland_sysctl (td=, name=0xfffffe0462180830, namelen=2, old=, oldlenp=, inkernel=, new=, newlen=, retval=, flags=0) at /usr/src/sys/kern/kern_sysctl.c:1633 #7 0xffffffff80980f24 in sys___sysctl (td=0xfffff80079fd3a00, uap=0xfffffe0462180940) at /usr/src/sys/kern/kern_sysctl.c:1568 #8 0xffffffff80db4e26 in amd64_syscall (td=0xfffff80079fd3a00, traced=0) at subr_syscall.c:141 #9 0xffffffff80d97d3b in Xfast_syscall () at /usr/src/sys/amd64/amd64/exception.S:398 #10 0x0000000802d8e69a in ?? () (kgdb) frame 6 #6 0xffffffff8098109c in userland_sysctl (td=, name=0xfffffe0462180830, namelen=2, old=, oldlenp=, inkernel=, new=, newlen=, retval=, flags=0) at /usr/src/sys/kern/kern_sysctl.c:1633 1633 sx_xlock(&sysctlmemlock); (kgdb) l 1628 ktrsysctl(name, namelen); 1629 #endif 1630 1631 if (req.oldlen > PAGE_SIZE) { 1632 memlocked = 1; 1633 sx_xlock(&sysctlmemlock); 1634 } else 1635 memlocked = 0; 1636 CURVNET_SET(TD_TO_VNET(td)); (kgdb) p req $1 = {td = 0xfffff80079fd3a00, lock = 1, oldptr = 0x0, oldlen = 140737488349408, oldidx = 0, oldfunc = 0xffffffff80980d10 , newptr = 0x0, newlen = 0, newidx = 0, newfunc = 0xffffffff80981190 , validlen = 140737488349408, flags = 0} (kgdb) p sysctlmemlock $2 = {lock_object = {lo_name = 0xffffffff81067d73 "sysctl mem", lo_flags = 36896768, lo_data = 0, lo_witness = 0xfffffe00006fee00}, sx_lock = 18446735279663165444} $3 = {w_name = "sysctl mem", '\0' , w_index = 92, w_class = 0xffffffff81579728, w_list = {stqe_next = 0xfffffe00006fed80}, w_typelist = {stqe_next = 0xfffffe00006fed80}, w_hash_next = 0xfffffe00006fc500, w_file = 0xffffffff81067ba3 "/usr/src/sys/kern/kern_sysctl.c", w_line = 1633, w_refcount = 1, w_num_ancestors = 0, w_num_descendants = 275, w_ddb_level = 0, w_displayed = 0, w_reversed = 0}