Memory allocation failures on a small ARM access point
A user ran a USB 802.11n adapter on a small ARM storage appliance (128 MB of RAM) as an access point with a handful of clients, alongside a USB drive and a printer server.
The kernel logged an order-3 page allocation failure in the receive path. A developer replied that a receive-path problem clearly existed. The user planned to capture more logs if it repeated.
Takeaway. Devices with little memory can fail on large contiguous allocations. Record the free-memory figures and the full allocation trace when it happens.