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