Failed GFP_ATOMIC allocations (dropped network packets) result in kernel warnings and backtrace

Issue

• Failed GFP_ATOMIC allocations by the network stack result in dropped packets with the following message as seen from the console:

page allocation failure. order:2, mode:0x4020

• These errors will be followed by a backtrace that shows similar characteristics to the following though the module affected is usually different:

kernel: ksoftirqd/0: page allocation failure. order:1, mode:0x20
kernel: Pid: 4, comm: ksoftirqd/0 Tainted: P           ---------------    2.6.32-358.el6.x86_64 #1
kernel: Call Trace:
kernel: <IRQ>  [<ffffffff8112c127>] ? __alloc_pages_nodemask+0x757/0x8d0
kernel: [<ffffffff811669d2>] ? kmem_getpages+0x62/0x170
kernel: [<ffffffff811675ea>] ? fallback_alloc+0x1ba/0x270
kernel: [<ffffffff8116703f>] ? cache_grow+0x2cf/0x320
kernel: [<ffffffff81167369>] ? ____cache_alloc_node+0x99/0x160
kernel: [<ffffffff81168530>] ? kmem_cache_alloc_node_trace+0x90/0x200
kernel: [<ffffffff8116874d>] ? __kmalloc_node+0x4d/0x60
kernel: [<ffffffff8143d6ad>] ? __alloc_skb+0x6d/0x190
kernel: [<ffffffff8143d7ed>] ? dev_alloc_skb+0x1d/0x40
kernel: [<ffffffffa0d01174>] ? ipoib_alloc_rx_skb+0x44/0x200 [ib_ipoib]
kernel: [<ffffffffa0d013cf>] ? ipoib_ib_handle_rx_wc+0x9f/0x590 [ib_ipoib]
kernel: [<ffffffffa0d01977>] ? ipoib_poll+0xb7/0x160 [ib_ipoib]
kernel: [<ffffffff8144cd43>] ? net_rx_action+0x103/0x2f0
kernel: [<ffffffff81076fb1>] ? __do_softirq+0xc1/0x1e0
kernel: [<ffffffff8100c1cc>] ? call_softirq+0x1c/0x30
kernel: <EOI>  [<ffffffff8100de05>] ? do_softirq+0x65/0xa0