Hang in sched_balance_self()

Jack Steiner
2005-06-03T22:55:53Z

Nick -

The latest 2.6.12-rc5-mm2 tree fails to boot on some of the 64p
SGI systems. The system hangs immediately after printing:

...
Inode-cache hash table entries: 8388608 (order: 12, 67108864 bytes)
Mount-cache hash table entries: 1024
Boot processor id 0x0/0x0
Brought up 64 CPUs
Total of 64 processors activated (118415.36 BogoMIPS).

I have isolated the failure to cpu 0 hanging in sched_balance_self() during
a fork (or clone). The "while" loop at the end of function never
terminates, ie. sd is never NULL.

Is this a problem that you have seen before. If not, I'll do some
more digging & isolate the problem.

--
Thanks

Jack Steiner (steiner@sgi.com) 651-683-5302
Principal Engineer SGI - Silicon Graphics, Inc.