Backtrace:
db:0:kdb.enter.default> bt Tracing pid 11 tid 100007 td 0xfffffe0003fd6720 kdb_enter() at kdb_enter+0x32/frame 0xfffffe000379d9c0 vpanic() at vpanic+0x183/frame 0xfffffe000379da10 panic() at panic+0x43/frame 0xfffffe000379da70 trap_fatal() at trap_fatal+0x409/frame 0xfffffe000379dad0 trap_pfault() at trap_pfault+0x4f/frame 0xfffffe000379db30 calltrap() at calltrap+0x8/frame 0xfffffe000379db30 --- trap 0xc, rip = 0xffffffff80b05c80, rsp = 0xfffffe000379dc00, rbp = 0xfffffe000379dc00 --- vmxnet3_isc_txd_credits_update() at vmxnet3_isc_txd_credits_update+0x20/frame 0xfffffe000379dc00 iflib_fast_intr_rxtx() at iflib_fast_intr_rxtx+0xf7/frame 0xfffffe000379dc60 intr_event_handle() at intr_event_handle+0x123/frame 0xfffffe000379dcd0 intr_execute_handlers() at intr_execute_handlers+0x4a/frame 0xfffffe000379dd00 Xapic_isr1() at Xapic_isr1+0xdc/frame 0xfffffe000379dd00 --- interrupt, rip = 0xffffffff8125b026, rsp = 0xfffffe000379ddd0, rbp = 0xfffffe000379ddd0 --- acpi_cpu_c1() at acpi_cpu_c1+0x6/frame 0xfffffe000379ddd0 acpi_cpu_idle() at acpi_cpu_idle+0x2fe/frame 0xfffffe000379de10 cpu_idle_acpi() at cpu_idle_acpi+0x48/frame 0xfffffe000379de30 cpu_idle() at cpu_idle+0x9e/frame 0xfffffe000379de50 sched_idletd() at sched_idletd+0x4d1/frame 0xfffffe000379def0 fork_exit() at fork_exit+0x7d/frame 0xfffffe000379df30 fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe000379df30 --- trap 0, rip = 0, rsp = 0, rbp = 0 ---We've seen that a few times and looked into it. We submitted a bug fix for it upstream: https://reviews.freebsd.org/D43712
Disabling multi-queue support prevents it if you're hitting it repeatedly.
Increasing the descriptor counts in the tunables will make it happen less frequently. But will still eventually hit it.
Steve