Help Implementing Adaptive RED ALTQ in FreeBSD

[Archit Pandey]

Hello all!

We are working on implementing Adaptive RED over existing RED code. Our
changes can be found on the adaptive-red branch on our repository
<https://github.com/archit-p/freebsd-adaptive-red>.

While running the custom kernel, the kernel panics and shuts down. We
have obtained the stack backtrace but are unable to pinpoint at where
the error is arising from. The backtrace is included here.


#0  doadump (textdump=<value optimized out>) at pcpu.h:229
#1  0xffffffff80af9c1b in kern_reboot (howto=260)
    at /usr/src/sys/kern/kern_shutdown.c:383
#2  0xffffffff80afa041 in vpanic (fmt=<value optimized out>,
    ap=<value optimized out>) at /usr/src/sys/kern/kern_shutdown.c:776
#3  0xffffffff80af9e83 in panic (fmt=<value optimized out>)
    at /usr/src/sys/kern/kern_shutdown.c:707
#4  0xffffffff80faefaf in trap_fatal (frame=0xfffffe0115725640, eva=0)
    at /usr/src/sys/amd64/amd64/trap.c:875
#5  0xffffffff80faf009 in trap_pfault (frame=0xfffffe0115725640, usermode=0)
    at pcpu.h:229
#6  0xffffffff80fae7d7 in trap (frame=0xfffffe0115725640)
    at /usr/src/sys/amd64/amd64/trap.c:415
#7  0xffffffff80f8f02c in calltrap ()
    at /usr/src/sys/amd64/amd64/exception.S:231
#8  0xffffffff80b11b88 in callout_process (now=2354690236789)
    at /usr/src/sys/kern/kern_timeout.c:508
#9  0xffffffff810e6b58 in handleevents (now=2354690236789, fake=0)
    at /usr/src/sys/kern/kern_clocksource.c:211
#10 0xffffffff810e71c9 in timercb (et=0xffffffff81e88a30,
    arg=<value optimized out>) at /usr/src/sys/kern/kern_clocksource.c:351
#11 0xffffffff81123831 in lapic_handle_timer (frame=0xfffffe0115725860)
    at /usr/src/sys/x86/x86/local_apic.c:1299
#12 0xffffffff80f90af5 in Xtimerint () at apic_vector.S:132
#13 0xffffffff8111a7f6 in acpi_cpu_c1 ()
    at /usr/src/sys/x86/x86/cpu_machdep.c:144
#14 0xffffffff803cbdc7 in acpi_cpu_idle (sbt=<value optimized out>)
    at /usr/src/sys/dev/acpica/acpi_cpu.c:1150
#15 0xffffffff8111ae5f in cpu_idle_acpi (sbt=39068816)
    at /usr/src/sys/x86/x86/cpu_machdep.c:452
#16 0xffffffff8111af05 in cpu_idle (busy=0)
    at /usr/src/sys/x86/x86/cpu_machdep.c:605
#17 0xffffffff80b2bdf4 in sched_idletd (dummy=<value optimized out>)
    at /usr/src/sys/kern/sched_ule.c:2834
#18 0xffffffff80abd583 in fork_exit (
    callout=0xffffffff80b2b8b0 <sched_idletd>, arg=0x0,
    frame=0xfffffe0115725ac0) at /usr/src/sys/kern/kern_fork.c:1054
#19 0xffffffff80f8ff4e in fork_trampoline ()
    at /usr/src/sys/amd64/amd64/exception.S:957
#20 0x0000000000000000 in ?? ()


We would really appreciate it if someone could review our code for
errors, or help us in making sense out of the stack backtrace.


Thanks and regards,

Archit Pandey.