I found a few ways to cause pages and pages of spew to dmesg
of the following form..

rhythmbox: page allocation failure. order:3, mode:0x4020
Pid: 4299, comm: rhythmbox Not tainted 2.6.25-0.172.rc7.git4.fc9.x86_64 #1

Call Trace:
 <IRQ>  [<ffffffff810862dc>] __alloc_pages+0x3a3/0x3c3
 [<ffffffff812a58df>] ? trace_hardirqs_on_thunk+0x35/0x3a
 [<ffffffff8109fd94>] alloc_pages_current+0x100/0x109
 [<ffffffff810a6fd5>] new_slab+0x4a/0x249
 [<ffffffff810a776a>] __slab_alloc+0x251/0x4e0
 [<ffffffff8121c322>] ? __netdev_alloc_skb+0x31/0x4f
 [<ffffffff810a8736>] __kmalloc_node_track_caller+0x8a/0xe2
 [<ffffffff8121c322>] ? __netdev_alloc_skb+0x31/0x4f
 [<ffffffff8121b5db>] __alloc_skb+0x6f/0x135
 [<ffffffff8121c322>] __netdev_alloc_skb+0x31/0x4f
 [<ffffffff8814e5b4>] :e1000e:e1000_alloc_rx_buffers+0xb7/0x1dc
 [<ffffffff8814eada>] :e1000e:e1000_clean_rx_irq+0x271/0x307
 [<ffffffff8814c71a>] :e1000e:e1000_clean+0x66/0x205
 [<ffffffff8121eeb8>] net_rx_action+0xd9/0x20e
 [<ffffffff81038757>] __do_softirq+0x70/0xf1
 [<ffffffff8100d25c>] call_softirq+0x1c/0x28
 [<ffffffff8100e485>] do_softirq+0x39/0x8a
 [<ffffffff81038290>] irq_exit+0x4e/0x8f
 [<ffffffff8100e781>] do_IRQ+0x145/0x167
 [<ffffffff8100c5e6>] ret_from_intr+0x0/0xf
 <EOI>  [<ffffffff812a5ed8>] ? _spin_unlock_irqrestore+0x42/0x47
 [<ffffffff8102a040>] ? __wake_up+0x43/0x50
 [<ffffffff81056b7f>] ? wake_futex+0x47/0x53
 [<ffffffff810584cf>] ? do_futex+0x697/0xc57
 [<ffffffff8102fbc4>] ? hrtick_set+0xa1/0xfc
 [<ffffffff81058b84>] ? sys_futex+0xf5/0x113
 [<ffffffff810133e7>] ? syscall_trace_enter+0xb5/0xb9
 [<ffffffff8100c1d0>] ? tracesys+0xd5/0xda

Given that we seem to recover from these events without negative effects
(ie, no apps get oom-killed), is there any value to actually flooding
syslog with this stuff ?

iirc, SuSE have been patching out these traces for GFP_ATOMIC allocations
for a long time.  Should mainline do the same ?

	Dave

-- 
http://www.codemonkey.org.uk