Re: kern/52034 (Kernel panic on Google Compute Engine)

[Benny Siegert <bsiegert%gmail.com@localhost>]

> With a non-DIAGNOSTIC kernel, there is no error or anything, it just
> tends to panic if you do disk-intensive workloads, e.g. unpacking a
> pkgsrc tarball.
> 
> I tried a DIAGNOSTIC kernel on -current (just before your fix) and had
> no problem. Will try the kernel with the refactored driver next.

I tried the following:

I downloaded http://nyftp.netbsd.org/pub/NetBSD-daily/netbsd-7-1/201706301130Z/amd64/binary/kernel/netbsd-GENERIC.gz. This identifies as NetBSD 7.1.0_PATCH (GENERIC.201706301130Z).

Unpacking a pkgsrc tarball makes the whole machine hang after a few minutes; I can see disk activity going to 0 in external monitoring. Breaking into ddb at this point shows that the machine is „idle“ and all processes with disk access are in tstile:

fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff8028259d cs 8 rflags 202 cr2 ffff80008af4e000 ilevel 8 rsp fffffe810da84d00
curlwp 0xfffffe821f770840 pid 0.2 lowest kstack 0xfffffe810da822c0
Stopped in pid 0.2 (system) at  netbsd:breakpoint+0x5:  leave
db{0}> bt
breakpoint() at netbsd:breakpoint+0x5
comintr() at netbsd:comintr+0x524
Xintr_ioapic_edge4() at netbsd:Xintr_ioapic_edge4+0xea
--- interrupt ---
x86_stihlt() at netbsd:x86_stihlt+0x6
acpicpu_cstate_idle_enter() at netbsd:acpicpu_cstate_idle_enter+0xc2
acpicpu_cstate_idle() at netbsd:acpicpu_cstate_idle+0x6d
idle_loop() at netbsd:idle_loop+0xe8
db{0}> ps
PID    LID S CPU     FLAGS       STRUCT LWP *               NAME WAIT
107      1 3   1         0   fffffe8117b405c0               cron tstile
826      1 3   0         0   fffffe821d9b6660                tar tstile
831      1 3   0        80   fffffe8117b401a0              xzcat pipe_wr
510      1 3   1        80   fffffe810e23e120                ksh pause
623      1 3   0        80   fffffe810e23e540               sshd select
661      1 3   0        80   fffffe810e20d940               sshd select
677      1 3   1         0   fffffe810e217980              getty tstile
804      1 3   1        80   fffffe821dae7600               cron nanoslp
636      1 3   0        80   fffffe821be8dac0              inetd kqueue
461      1 3   1        80   fffffe8167ed81c0               qmgr kqueue
605      1 3   0        80   fffffe821d9b3200             pickup kqueue
753      1 3   1        80   fffffe821bba4260             master kqueue
507      1 3   0        80   fffffe821da84220               sshd select
435      1 3   1        80   fffffe821dae7a20             powerd kqueue
295      1 3   1         0   fffffe821dae71e0            syslogd tstile
249      1 3   0        80   fffffe8167ed8a00             dhcpcd kqueue
1        1 3   1        80   fffffe810e39d9a0               init wait
0       42 3   0       200   fffffe810eade9c0            physiod physiod
0       41 3   1       200   fffffe8117b409e0           aiodoned aiodoned
0       40 3   1       200   fffffe810eade180            ioflush tstile
0       39 3   1       200   fffffe810eade5a0           pgdaemon pgdaemon