Re: [lkp] [printk] 34578dc67f: EIP is at vprintk_emit+0x1ea/0x600

Sergey Senozhatsky
2016-02-23T15:55:32Z

On (02/23/16 22:15), Sergey Senozhatsky wrote:
> On (02/23/16 08:55), kernel test robot wrote:
> > [ 33.497678] ### dt-test ### of_unittest_destroy_tracked_overlays: overlay destroy failed for #6
> > [ 33.497693] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [swapper:1]
> > [ 33.497693] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [swapper:1]
> > [ 33.497695] Modules linked in:
> > [ 33.497695] Modules linked in:
> > [ 33.497696] irq event stamp: 69018756
> > [ 33.497696] irq event stamp: 69018756
>
> how may consoles do you have registered? is it possible that your
> call_console_drivers() loop push the same data to different consoles,
> but the messages end up in one place (serial port, etc... dunno)?
> does it happen to all of the messages?

oh... didn't notice there was a dmesg.xz attached.

ok, so everything is "doubled" in your dmesg, starting from "console [ttyS0] enabled" line

254 [ 0.000000] vmalloc : 0xc47e0000 - 0xff7fe000 ( 944 MB)
255 [ 0.000000] lowmem : 0xb0000000 - 0xc3fe0000 ( 319 MB)
256 [ 0.000000] .init : 0xc0dc4000 - 0xc0e3a000 ( 472 kB)
257 [ 0.000000] .data : 0xc0a0a040 - 0xc0dc2560 (3809 kB)
258 [ 0.000000] .text : 0xc0600000 - 0xc0a0a040 (4136 kB)
259 [ 0.000000] Checking if this processor honours the WP bit even in supervisor mode...Ok.
260 [ 0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
261 [ 0.000000] Running RCU self tests
262 [ 0.000000] NR_IRQS:2304 nr_irqs:256 16
263 [ 0.000000] CPU 0 irqstacks, hard=b002a000 soft=b002c000
264 [ 0.000000] console [ttyS0] enabled
265 [ 0.000000] console [ttyS0] enabled
266 [ 0.000000] Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar
267 [ 0.000000] Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar
268 [ 0.000000] ... MAX_LOCKDEP_SUBCLASSES: 8
269 [ 0.000000] ... MAX_LOCKDEP_SUBCLASSES: 8
270 [ 0.000000] ... MAX_LOCK_DEPTH: 48
271 [ 0.000000] ... MAX_LOCK_DEPTH: 48
272 [ 0.000000] ... MAX_LOCKDEP_KEYS: 8191
273 [ 0.000000] ... MAX_LOCKDEP_KEYS: 8191
274 [ 0.000000] ... CLASSHASH_SIZE: 4096
275 [ 0.000000] ... CLASSHASH_SIZE: 4096
276 [ 0.000000] ... MAX_LOCKDEP_ENTRIES: 32768
277 [ 0.000000] ... MAX_LOCKDEP_ENTRIES: 32768
278 [ 0.000000] ... MAX_LOCKDEP_CHAINS: 65536
279 [ 0.000000] ... MAX_LOCKDEP_CHAINS: 65536
280 [ 0.000000] ... CHAINHASH_SIZE: 32768
281 [ 0.000000] ... CHAINHASH_SIZE: 32768
282 [ 0.000000] memory used by lock dependency info: 5167 kB
283 [ 0.000000] memory used by lock dependency info: 5167 kB
284 [ 0.000000] per task-struct memory footprint: 2112 bytes
285 [ 0.000000] per task-struct memory footprint: 2112 bytes
286 [ 0.000000] ------------------------
287 [ 0.000000] ------------------------
288 [ 0.000000] | Locking API testsuite:
289 [ 0.000000] | Locking API testsuite:
290 [ 0.000000] ----------------------------------------------------------------------------
291 [ 0.000000] ----------------------------------------------------------------------------
292 [ 0.000000] | spin |wlock |rlock |mutex | wsem | rsem |
293 [ 0.000000] | spin |wlock |rlock |mutex | wsem | rsem |
294 [ 0.000000] --------------------------------------------------------------------------
295 [ 0.000000] --------------------------------------------------------------------------

looking at your Kernel command line

[ 0.000000] Kernel command line: root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-kbuild-yocto-i386-53/bisect_boot-1-yocto-minimal-i386.cgz-i386-randconfig-h1-02192137-34578dc67f38c02ccbe696e4099967884caa8e15-20160220-72722-vao2m5-0.yaml ARCH=i386 kconfig=i386-randconfig-h1-02192137 branch=linux-next/master commi t=34578dc67f38c02ccbe696e4099967884caa8e15 BOOT_IMAGE=/pkg/linux/i386-randconfig-h1-02192137/gcc-5/34578dc67f38c02ccbe696e4099967884caa8e15/vmlinuz-4.5.0-rc4-00295-g34578dc max_uptime=600 RESULT_ROOT=/result/boot/1/vm-kbuild-yocto-i386/yocto-minimal-i386.cgz/i386-randconfig-h1-02192137/gcc-5/34578dc67f38c02ccbe69 6e4099967884caa8e15/9 LKP_SERVER=inn earlyprintk=ttyS0,115200 systemd.log_level=err debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 console=ttyS0,115200 console=tty0 vga=normal rw ip=::::vm-kbuild-yo cto-i386-53::dhcp drbd.minor_count=8

- earlyprintk=ttyS0,115200
- console=ttyS0,115200
- console=tty0

so you have two consoles: ttyS0 and tty0?

and I see "bootconsole [earlyser0] enabled" but no "bootconsole [earlyser0] disabled" message, which
I'd expect to see...

So how may consoles do you have? 2 or 3? so call_console_drivers() has to ->write()
every log line N times; at least to ttyS0->write() and to tty0->write()?

-ss