Re: rcu_init allocation failure trace on bootup

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

On Mon, May 06, 2013 at 04:24:13PM -0400, Dave Jones wrote:
> On Mon, May 06, 2013 at 12:43:51PM -0700, Paul E. McKenney wrote:
>  > On Mon, May 06, 2013 at 03:26:53PM -0400, Dave Jones wrote:
>  > > On Mon, May 06, 2013 at 12:05:22PM -0700, Paul E. McKenney wrote:
>  > >  > On Mon, May 06, 2013 at 01:56:47PM -0400, Dave Jones wrote:
>  > >  > > [    0.000000]  RCU debugfs-based tracing is enabled.
>  > >  > > [    0.000000]  RCU lockdep checking is enabled.
>  > >  > > [    0.000000] ------------[ cut here ]------------
>  > >  > > [    0.000000] WARNING: at mm/nobootmem.c:215 ___alloc_bootmem_nopanic+0x3a/0x7d()
>  > >  > > [    0.000000] Modules linked in:
>  > >  > > [    0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.9.0+ #128
>  > >  > > [    0.000000] Hardware name:                  /D975XBX, BIOS BX97510J.86A.1209.2006.0601.1340 06/01/2006
>  > >  > > [    0.000000]  ffffffff819f4246 ffffffff81c01e68 ffffffff816a0db2 ffffffff81c01ea8
>  > >  > > [    0.000000]  ffffffff8104b1a0 ffffffff819e1078 0000000000000000 0000000000000008
>  > >  > > [    0.000000]  ffffffffffffffff 0000000000000040 0000000000000000 ffffffff81c01eb8
>  > >  > > [    0.000000] Call Trace:
>  > >  > > [    0.000000]  [<ffffffff816a0db2>] dump_stack+0x19/0x1b
>  > >  > > [    0.000000]  [<ffffffff8104b1a0>] warn_slowpath_common+0x70/0xa0
>  > >  > > [    0.000000]  [<ffffffff8104b1ea>] warn_slowpath_null+0x1a/0x20
>  > >  > > [    0.000000]  [<ffffffff81ef8914>] ___alloc_bootmem_nopanic+0x3a/0x7d
>  > >  > > [    0.000000]  [<ffffffff81ef8b87>] __alloc_bootmem+0x13/0x39
>  > >  > > [    0.000000]  [<ffffffff81f090ad>] alloc_bootmem_cpumask_var+0x1a/0x21
>  > >  > > [    0.000000]  [<ffffffff81ef1f5a>] rcu_init+0x7f/0x261
>  > >  > > [    0.000000]  [<ffffffff81ef4acb>] ? perf_event_init+0x178/0x181
>  > >  > > [    0.000000]  [<ffffffff81ed6c79>] start_kernel+0x232/0x3d3
>  > >  > > [    0.000000]  [<ffffffff81ed6846>] ? repair_env_string+0x5e/0x5e
>  > >  > > [    0.000000]  [<ffffffff81ed6577>] x86_64_start_reservations+0x2a/0x2c
>  > >  > > [    0.000000]  [<ffffffff81ed6646>] x86_64_start_kernel+0xcd/0xd1
>  > >  > > [    0.000000] ---[ end trace 0acfc82c197165dd ]---
>  > >  > > [    0.000000]  Experimental no-CBs for all CPUs
>  > >  > > [    0.000000]  Experimental no-CBs CPUs: 0-1.
>  > >  > > [    0.000000] NO_HZ: Full dynticks CPUs: 1.
>  > >  > 
>  > >  > Do you have commit fa0f93cd6a (rcu: Don't allocate bootmem from rcu_init())?
>  > >  > If not, could you please try applying it?
>  > > 
>  > > That commit isn't in Linus tree.
>  > 
>  > You are quite right, I am getting ahead of myself.  Please see below
>  > for the patch.
> 
> Doesn't fix it for me.
> 
> Is it this one instead perhaps ?
> 
>   89 #ifndef CONFIG_RCU_NOCB_CPU_NONE
>   90         if (!have_rcu_nocb_mask) {
>   91                 alloc_bootmem_cpumask_var(&rcu_nocb_mask);
>   92                 have_rcu_nocb_mask = true;
>   93         }

Hmmm...  That was in fact the one that the patch was intended to change.
Just out of curiosity, where did the patch apply instead?

							Thanx, Paul