A week ago I updated one of my servers to 2.6.25-rc6 and today looking
through logs I've found these:

[380219.823434] ------------[ cut here ]------------
[380219.823450] WARNING: at net/ipv4/tcp_input.c:2510 tcp_ack+0xc7e/0x177d()
[380219.823463] Pid: 0, comm: swapper Not tainted 2.6.25-rc6-dirty #1
[380219.823477]  [<c0118cee>] warn_on_slowpath+0x3b/0x4a
[380219.823494]  [<c0205f66>] boomerang_rx+0x346/0x371
[380219.823517]  [<c0206fa2>] boomerang_interrupt+0x288/0x2c0
[380219.823528]  [<c010e62b>] ack_ioapic_quirk_irq+0x9/0x82
[380219.823560]  [<c01320bd>] handle_fasteoi_irq+0x7c/0xa4
[380219.823589]  [<c0104e8b>] do_IRQ+0x73/0x84
[380219.823606]  [<c01033df>] common_interrupt+0x23/0x28
[380219.823616]  [<c02cd646>] tcp_ack+0xc7e/0x177d
[380219.823632]  [<c02d0691>] tcp_rcv_established+0xe1/0x66c
[380219.823643]  [<c02b6bf8>] nf_iterate+0x30/0x63
[380219.823666]  [<c02d5429>] tcp_v4_do_rcv+0x1f/0x175
[380219.823680]  [<c02d690d>] tcp_v4_rcv+0x4fb/0x53f
[380219.823691]  [<c02c0345>] ip_local_deliver_finish+0x94/0xfc
[380219.823708]  [<c02c0292>] ip_rcv_finish+0x23a/0x259
[380219.823719]  [<c02c0657>] ip_rcv+0x1eb/0x223
[380219.823728]  [<c02c0058>] ip_rcv_finish+0x0/0x259
[380219.823738]  [<c02a7c5b>] netif_receive_skb+0x1b0/0x1c7
[380219.823764]  [<c02a9de2>] process_backlog+0x6a/0xbb
[380219.823785]  [<c02a98a1>] net_rx_action+0x63/0x131
[380219.823796]  [<c011cc88>] __do_softirq+0x6c/0xcf
[380219.823812]  [<c011cd1d>] do_softirq+0x32/0x36
[380219.823827]  [<c0104e8b>] do_IRQ+0x73/0x84
[380219.823837]  [<c01033df>] common_interrupt+0x23/0x28
[380219.823846]  [<c012007b>] update_process_times+0x1c/0x44
[380219.823858]  [<c01018e9>] default_idle+0x36/0x58
[380219.823872]  [<c01018b3>] default_idle+0x0/0x58
[380219.823881]  [<c0101802>] cpu_idle+0x81/0x95
[380219.823891]  =======================
[380219.823898] ---[ end trace 6fe07dd16e237875 ]---
[382618.087140] ------------[ cut here ]------------
[382618.087140] ------------[ cut here ]------------
[382618.087140] WARNING: at net/ipv4/tcp_input.c:2510 tcp_ack+0xc7e/0x177d()
[382618.087140] Pid: 0, comm: swapper Not tainted 2.6.25-rc6-dirty #1
[382618.087140]  [<c0118cee>] warn_on_slowpath+0x3b/0x4a
[382618.087140]  [<c0205f66>] boomerang_rx+0x346/0x371
[382618.087140]  [<c0205f66>] boomerang_rx+0x346/0x371
[382618.087146]  [<c0206fa2>] boomerang_interrupt+0x288/0x2c0
[382618.087163]  [<c010e62b>] ack_ioapic_quirk_irq+0x9/0x82
[382618.087189]  [<c01320bd>] handle_fasteoi_irq+0x7c/0xa4
[382618.087215]  [<c0104e8b>] do_IRQ+0x73/0x84
[382618.087239]  [<c01033df>] common_interrupt+0x23/0x28
[382618.087250]  [<c01c007b>] sys_mq_open+0x1c2/0x230
[382618.087280]  [<c02a3a52>] skb_release_data+0x2b/0x81
[382618.087295]  [<c02cd646>] tcp_ack+0xc7e/0x177d
[382618.087306]  [<c02d0691>] tcp_rcv_established+0xe1/0x66c
[382618.087322]  [<c02b6bf8>] nf_iterate+0x30/0x63
[382618.087337]  [<c02d5429>] tcp_v4_do_rcv+0x1f/0x175
[382618.087358]  [<c02d690d>] tcp_v4_rcv+0x4fb/0x53f
[382618.087369]  [<c02c0345>] ip_local_deliver_finish+0x94/0xfc
[382618.087380]  [<c02c0292>] ip_rcv_finish+0x23a/0x259
[382618.087396]  [<c02c0657>] ip_rcv+0x1eb/0x223
[382618.087406]  [<c02c0058>] ip_rcv_finish+0x0/0x259
[382618.087415]  [<c02a7c5b>] netif_receive_skb+0x1b0/0x1c7
[382618.087440]  [<c02a9de2>] process_backlog+0x6a/0xbb
[382618.087454]  [<c02a98a1>] net_rx_action+0x63/0x131
[382618.087464]  [<c011cc88>] __do_softirq+0x6c/0xcf
[382618.087486]  [<c011cd1d>] do_softirq+0x32/0x36
[382618.087496]  [<c0104e8b>] do_IRQ+0x73/0x84
[382618.087505]  [<c01033df>] common_interrupt+0x23/0x28
[382618.087519]  [<c012007b>] update_process_times+0x1c/0x44
[382618.087530]  [<c01018e9>] default_idle+0x36/0x58
[382618.087540]  [<c01018b3>] default_idle+0x0/0x58
[382618.087554]  [<c0101802>] cpu_idle+0x81/0x95
[382618.087564]  =======================
[382618.087571] ---[ end trace 6fe07dd16e237875 ]---

The kernel config is attached.

-- 
Georgi Chorbadzhiyski
http://georgi.unixsol.org/