Hi Akinobu,

FYI, kernel build failed on

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm
head:   d28e1f373a79e532eecbe6b17beeb4d2052c1a52
commit: eb918a7ea0c312c61c3f45d104d71f95f10a5adf [46/246] cciss: use check_signature
config: i386-randconfig-b997 (attached as .config)

All related error/warning messages:

drivers/built-in.o: In function `CISS_signature_present':
drivers/block/cciss.c:4270: undefined reference to `check_signature'

The above error looks persistent, at least it still exists several
commits later, in [50/246] e1f762d block: partition: msdos: provide UUIDs for partitions

net/built-in.o: In function `sock_edemux':
net/core/sock.c:1529: undefined reference to `inet_twsk_put'

The above error is an unrelated one.

---
0-DAY kernel build testing backend         Open Source Technology Centre
Fengguang Wu <wfg@linux.intel.com>                     Intel Corporation