[CentOS] swapper: page allocation failure. order:1, mode:0x20

Fri Oct 19 00:02:03 UTC 2012
Stephen Harris <lists at spuddy.org>

On Thu, Oct 18, 2012 at 03:44:30PM -0500, Tim Nelson wrote:
> Oct 18 03:10:52 backup kernel: Pid: 0, comm: swapper Not tainted 2.6.32-279.9.1.el6.x86_64 #1


> Oct 18 03:10:52 backup kernel: [<ffffffff814927ed>] ? tcp_v4_syn_recv_sock+0x4d/0x310
> Oct 18 03:10:52 backup kernel: [<ffffffff81494d26>] ? tcp_check_req+0x226/0x460
> Oct 18 03:10:52 backup kernel: [<ffffffff8148a6d6>] ? tcp_rcv_state_process+0x126/0xa10

> Any thoughts on the cause? The system has 16GB of RAM, and whenever

It's not a normal "out of memory" error.

> checked, there is no swap usage. Is this a memory error (bad RAM)?

I see this sometimes on my linode using their custom kernel when doing
lots of network communication (rsync'ing files).  It looks like an
issue with the TCP/IP4 stack.  When I switched to IP6 then the messages
went away.