8870 do not lock cpu when waiting for IBF or OBF

[procmonk]

commit 8ad8a2c4a4abef9af95f1033b18eecffe4860896
Author: jhb jhb@FreeBSD.org
Date: Mon Dec 22 16:53:04 2014 +0000

Explicitly treat timeouts when waiting for IBF or OBF to change state as an
error.  This fixes occasional hangs in the IPMI kcs thread when using
ipmitool locally.

MFC after:  1 week

[danmcd]

We generally don't do PRs directly, but if you're doing this to provide a place for review, that's fine.

[procmonk]

For the moment, my only success is to panic my test node.
``

$C
ffffff00202e9010 lwp_kernel_create+0x31(0, fffffffffbb17680, ffffff0502a4b6a8, 2, 3c)
ffffff00202e9060 taskq_thread_create+0x62(ffffff0502a4b6a8)
ffffff00202e9110 taskq_create_common+0x1af(fffffffff81c5cb6, 0, 1, 3c, 1, 1, 0, 0, 40001)
ffffff00202e9170 taskq_create_proc+0x4d(fffffffff81c5cb6, 1, 3c, 1, 1, 0, ffffffff00000001)
ffffff00202e91b0 kcs_startup+0x5b(ffffffffc01abea0)
ffffff00202e9210 ipmi_startup+0x52(ffffffffc01abea0)
ffffff00202e9240 ipmi_attach+0x10f(ffffff04ff7eb008, 0)
ffffff00202e92b0 devi_attach+0x92(ffffff04ff7eb008, 0)
ffffff00202e92f0 attach_node+0xa7(ffffff04ff7eb008)
ffffff00202e9340 i_ndi_config_node+0x7d(ffffff04ff7eb008, 6, 0)
ffffff00202e9370 i_ddi_attachchild+0x48(ffffff04ff7eb008)
ffffff00202e93b0 devi_attach_node+0x5e(ffffff04ff7eb008, 4000)
ffffff00202e94b0 devi_config_one+0x294(ffffff04e59bcaa8, ffffff00202e97a0, ffffff00202e9588, 4000, 0)
ffffff00202e9520 ndi_devi_config_one+0xa8(ffffff04e59bcaa8, ffffff00202e97a0, ffffff00202e9588, 4000)
ffffff00202e9600 dv_find+0x233(ffffff04ea8cbdc8, ffffff00202e97a0, ffffff00202e98e8, ffffff00202e9a70,
ffffff04ea81cc00, ffffff04ff939460, ffffff0000000000)
ffffff00202e9650 devfs_lookup+0x37(ffffff04eab35c00, ffffff00202e97a0, ffffff00202e98e8, ffffff00202e9a70, 0,
ffffff04ea81cc00, ffffff04ff939460, 0, 0, 0)
ffffff00202e9700 fop_lookup+0xa2(ffffff04eab35c00, ffffff00202e97a0, ffffff00202e98e8, ffffff00202e9a70, 0,
ffffff04ea81cc00, ffffff04ff939460, 0, 0, 0)
ffffff00202e9950 lookuppnvp+0x1fe(ffffff00202e9a70, 0, 1, 0, ffffff00202e9c88, ffffff04ea81cc00, ffffff04ea81cc00,
ffffff04ff939460)
ffffff00202e99f0 lookuppnatcred+0x15e(ffffff00202e9a70, 0, 1, 0, ffffff00202e9c88, 0, ffffff04ff939460)
ffffff00202e9af0 lookupnameatcred+0xad(fe6b9430, 0, 1, 0, ffffff00202e9c88, 0, ffffff04ff939460)
ffffff00202e9b40 lookupnameat+0x39(fe6b9430, 0, 1, 0, ffffff00202e9c88, 0)
ffffff00202e9cf0 vn_openat+0x315(fe6b9430, 0, 3, 840, ffffff00202e9e00, 0, ffffff0000000012, 0, ffffff050000000c)
ffffff00202e9e60 copen+0x20c(ffd19553, fe6b9430, 3, 840)
ffffff00202e9e90 openat32+0x27(ffd19553, fe6b9430, 2, 840)
ffffff00202e9ec0 open32+0x25(fe6b9430, 2, 840)
ffffff00202e9f10 sys_syscall32+0xff()

``

[procmonk]

Will build via the correct release, as you suggested by email.