Re: [rcu:fixes.2012.07.06a 12/19] undefined reference to `rcu_is_cpu_idle'

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

On Sun, Jul 08, 2012 at 01:18:03AM +0800, wfg@linux.intel.com wrote:
> Hi Paul,
> 
> Kernel build failed on
> 
> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git fixes.2012.07.06a
> head:   cfca927972e31a5b3da49bf641c525732ff3c357
> commit: 62fde6edf12b60fddb13a3f0a779c8be0bb7447e [12/19] rcu: Make __call_rcu() handle invocation from idle
> config: x86_64-randconfig-tip4 (attached as .config)
> 
> 
> kernel/built-in.o: In function `rcu_read_lock_bh_held': (.text+0x167d1): undefined reference to `rcu_is_cpu_idle'
> kernel/built-in.o: In function `lockdep_rcu_suspicious': (.text+0x367e8): undefined reference to `rcu_is_cpu_idle'
> kernel/built-in.o: In function `lockdep_rcu_suspicious': (.text+0x36815): undefined reference to `rcu_is_cpu_idle'
> kernel/built-in.o: In function `css_get_next': (.text+0x40f5a): undefined reference to `rcu_is_cpu_idle'
> drivers/built-in.o: In function `dst_link_failure': isdn_net.c:(.text+0x13950a): undefined reference to `rcu_is_cpu_idle'
> net/built-in.o:sock.c:(.text+0x3cec): more undefined references to `rcu_is_cpu_idle' follow
> 
> There are more similar errors in the other randconfigs.

Hmmm...  So you are building TINY_RCU without CONFIG_DEBUG_LOCK_ALLOC,
but with some checking enabled.  I -thought- I was testing that...

But, wait.  You do have CONFIG_DEBUG_LOCK_ALLOC defined.  That really
should cause rcu_is_cpu_idle() to be compiled into kernel/rcupdate.o.
And your config builds on my system with no errors.

Was there perhaps another problem, maybe running out of disk space?

							Thanx, Paul