Hi, on which kernel version did you find this issue? Thanks!

As I said in original report this is under kernel-2.6.32-131.6.1.el6.x86_64. But I can also confirm this issue in at least two previous RPM packages kernels and the latest kernel-2.6.32-131.12.1.el6.x86_64 too.

Since RHEL 6.2 External Beta has begun, and this bug remains
unresolved, it has been rejected as it is not proposed as
exception or blocker.

Red Hat invites you to ask your support representative to
propose this request, if appropriate and relevant, in the
next release of Red Hat Enterprise Linux.

I think this it related to Bug #713546 .
https://bugzilla.redhat.com/show_bug.cgi?id=713546

The warning in this bug report is merely that - a warning from the kernel stating that it could not allocate an order 1 (2 contiguous pages) buffer for a network packet.

This should not cause either the system or httpd to hang or crash.

Vilius, does the system actually hang or crash?

If so, what is the kernel message (if any) showing the hang or crash?

If you have trouble identifying the information that will help engineering fix the issue, please contact Red Hat support so things can get properly analyzed before they get escalated to engineering.

Basically when this starts, I see more and more such messages. Sometimes messages are sent "from" httpd, sometimes from other software on the server, or for example the swapper:

Nov  4 22:21:04 post kernel: swapper: page allocation failure. order:1, mode:0x20
Nov  4 22:21:04 post kernel: Pid: 0, comm: swapper Not tainted 2.6.32-131.17.1.el6.x86_64 #1
Nov  4 22:21:04 post kernel: Call Trace:
Nov  4 22:21:04 post kernel: <IRQ>  [<ffffffff8112016e>] ? __alloc_pages_nodemask+0x71e/0x8b0
Nov  4 22:21:04 post kernel: [<ffffffff81159a52>] ? kmem_getpages+0x62/0x170
Nov  4 22:21:04 post kernel: [<ffffffff8115a66a>] ? fallback_alloc+0x1ba/0x270
Nov  4 22:21:04 post kernel: [<ffffffff8115a0bf>] ? cache_grow+0x2cf/0x320
Nov  4 22:21:04 post kernel: [<ffffffff8115a3e9>] ? ____cache_alloc_node+0x99/0x160
Nov  4 22:21:04 post kernel: [<ffffffff8115b1ab>] ? kmem_cache_alloc+0x11b/0x190
Nov  4 22:21:04 post kernel: [<ffffffff81411ba8>] ? sk_prot_alloc+0x48/0x1a0
Nov  4 22:21:04 post kernel: [<ffffffff81411e12>] ? sk_clone+0x22/0x2c0
Nov  4 22:21:04 post kernel: [<ffffffff8145caf6>] ? inet_csk_clone+0x16/0xd0
Nov  4 22:21:04 post kernel: [<ffffffff81475be3>] ? tcp_create_openreq_child+0x23/0x450
Nov  4 22:21:04 post kernel: [<ffffffff814735cd>] ? tcp_v4_syn_recv_sock+0x4d/0x2a0
Nov  4 22:21:04 post kernel: [<ffffffff814759a1>] ? tcp_check_req+0x201/0x420
Nov  4 22:21:04 post kernel: [<ffffffff81472feb>] ? tcp_v4_do_rcv+0x35b/0x430
Nov  4 22:21:04 post kernel: [<ffffffffa0261557>] ? ipv4_confirm+0x87/0x1d0 [nf_conntrack_ipv4]
Nov  4 22:21:04 post kernel: [<ffffffff81474760>] ? tcp_v4_rcv+0x4e0/0x860
Nov  4 22:21:04 post kernel: [<ffffffff814523a0>] ? ip_local_deliver_finish+0x0/0x2d0
Nov  4 22:21:04 post kernel: [<ffffffff81447804>] ? nf_hook_slow+0x74/0x100
Nov  4 22:21:04 post kernel: [<ffffffff814523a0>] ? ip_local_deliver_finish+0x0/0x2d0
Nov  4 22:21:04 post kernel: [<ffffffff8145247d>] ? ip_local_deliver_finish+0xdd/0x2d0
Nov  4 22:21:04 post kernel: [<ffffffff81452708>] ? ip_local_deliver+0x98/0xa0
Nov  4 22:21:04 post kernel: [<ffffffff81451bcd>] ? ip_rcv_finish+0x12d/0x440
Nov  4 22:21:04 post kernel: [<ffffffff81452155>] ? ip_rcv+0x275/0x350
Nov  4 22:21:04 post kernel: [<ffffffff8141dccb>] ? __netif_receive_skb+0x39b/0x6b0
Nov  4 22:21:04 post kernel: [<ffffffff8141ffd8>] ? netif_receive_skb+0x58/0x60
Nov  4 22:21:04 post kernel: [<ffffffff814200e0>] ? napi_skb_finish+0x50/0x70
Nov  4 22:21:04 post kernel: [<ffffffff81422419>] ? napi_gro_receive+0x39/0x50
Nov  4 22:21:04 post kernel: [<ffffffffa0169121>] ? tg3_poll_work+0x6b1/0xdf0 [tg3]
Nov  4 22:21:04 post kernel: [<ffffffffa02358b6>] ? destroy_conntrack+0xd6/0x150 [nf_conntrack]
Nov  4 22:21:04 post kernel: [<ffffffffa01698c4>] ? tg3_poll+0x64/0x210 [tg3]
Nov  4 22:21:04 post kernel: [<ffffffff81422533>] ? net_rx_action+0x103/0x2f0
Nov  4 22:21:04 post kernel: [<ffffffff8106f6e1>] ? __do_softirq+0xc1/0x1d0
Nov  4 22:21:04 post kernel: [<ffffffff8100c2cc>] ? call_softirq+0x1c/0x30
Nov  4 22:21:04 post kernel: [<ffffffff8100df05>] ? do_softirq+0x65/0xa0
Nov  4 22:21:04 post kernel: [<ffffffff8106f4c5>] ? irq_exit+0x85/0x90
Nov  4 22:21:04 post kernel: [<ffffffff814e3195>] ? do_IRQ+0x75/0xf0
Nov  4 22:21:04 post kernel: [<ffffffff8100bad3>] ? ret_from_intr+0x0/0x11
Nov  4 22:21:04 post kernel: <EOI>  [<ffffffff81014197>] ? mwait_idle+0x77/0xd0
Nov  4 22:21:04 post kernel: [<ffffffff814e09ea>] ? atomic_notifier_call_chain+0x1a/0x20
Nov  4 22:21:04 post kernel: [<ffffffff81009e86>] ? cpu_idle+0xb6/0x110
Nov  4 22:21:04 post kernel: [<ffffffff814d45da>] ? start_secondary+0x202/0x245


Server doesn't hand on every such message, but after a while it does. I will make a sceenshot of the last message next time this happens.

OK, I finally solved this myself. Had to upgrade 04:03.0 RAID bus controller: Compaq Computer Corporation Smart Array 64xx (rev 01) firmware. Now the system is stable. Not sure if this is a bug in the controller or in the kernel, so don't know how to close this bug report right. Leaving this for others to do.

Since all you ever got from the kernel was warnings that a network buffer could not be allocated - which results in a lost packet, that can be retransmitted later - I suspect that you simply had a correlation going on.

Lost network packets happen when system load is very high.

Having the RAID controller hang the system also happens when system load is very high.

If there was another bug in the kernel somewhere, you would have seen an error message to that effect.

Closing the bug, since it appears to have been a hardware issue.

I see this happening on RHEL6.5 too, running as a VM under ESXI 5.1. See http://karlsbakk.net/tmp/kernel-errors.gz for the errors.

roy