Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964802AbWIVRR6 (ORCPT ); Fri, 22 Sep 2006 13:17:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964799AbWIVRR6 (ORCPT ); Fri, 22 Sep 2006 13:17:58 -0400 Received: from mga02.intel.com ([134.134.136.20]:43034 "EHLO mga02.intel.com") by vger.kernel.org with ESMTP id S964782AbWIVRR4 (ORCPT ); Fri, 22 Sep 2006 13:17:56 -0400 X-ExtLoop1: 1 X-IronPort-AV: i="4.09,204,1157353200"; d="scan'208"; a="133328414:sNHT176489068" Message-ID: <4514190C.8010901@intel.com> Date: Fri, 22 Sep 2006 10:10:36 -0700 From: Auke Kok User-Agent: Mail/News 1.5.0.7 (X11/20060918) MIME-Version: 1.0 To: Andrew Morton CC: Holger Kiehl , linux-kernel , linux-net , netdev@vger.kernel.org, "Ronciak, John" Subject: Re: 2.6.1[78] page allocation failure. order:3, mode:0x20 References: <20060922004253.2e2e2612.akpm@osdl.org> In-Reply-To: <20060922004253.2e2e2612.akpm@osdl.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 22 Sep 2006 17:12:25.0281 (UTC) FILETIME=[463B0310:01C6DE6A] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5390 Lines: 122 Andrew Morton wrote: > On Fri, 22 Sep 2006 07:27:18 +0000 (GMT) > Holger Kiehl wrote: > >> I get some of the "page allocation failure" errors. My hardware is 4 CPU >> Opteron with one quad + one dual intel e1000 cards. Kernel is plain 2.6.18 >> and for two cards MTU is set to 9000. >> >> Sep 21 21:03:15 athena kernel: vsftpd: page allocation failure. order:3, mode:0x20 >> Sep 21 21:03:15 athena kernel: >> Sep 21 21:03:15 athena kernel: Call Trace: >> Sep 21 21:03:15 athena kernel: [] __alloc_pages+0x282/0x29b >> Sep 21 21:03:15 athena kernel: [] :ip_tables:ipt_do_table+0x1eb/0x318 >> Sep 21 21:03:15 athena kernel: [] cache_grow+0x134/0x33d >> Sep 21 21:03:15 athena kernel: [] cache_alloc_refill+0x189/0x1d7 >> Sep 21 21:03:15 athena kernel: [] __kmalloc+0x8a/0x94 >> Sep 21 21:03:15 athena kernel: [] __alloc_skb+0x5c/0x123 >> Sep 21 21:03:15 athena kernel: [] __netdev_alloc_skb+0x12/0x2d >> Sep 21 21:03:15 athena kernel: [] e1000_alloc_rx_buffers+0x6f/0x2f3 >> Sep 21 21:03:15 athena kernel: [] ip_local_deliver+0x173/0x23b >> Sep 21 21:03:15 athena kernel: [] e1000_clean_rx_irq+0x4f4/0x514 > > Is OK, it's just a warning and it is expected - the kernel will recover. > > I'm half-inclined to shut the warning up by sticking a __GFP_NOWARN in there. > > But on the other hand, that warning is handy sometimes. How come kmalloc > decided to request a 32k hunk of memory when the MTU size is only 9k? Is > the driver doing something dumb? > > else if (max_frame <= E1000_RXBUFFER_8192) > adapter->rx_buffer_len = E1000_RXBUFFER_8192; > else if (max_frame <= E1000_RXBUFFER_16384) > adapter->rx_buffer_len = E1000_RXBUFFER_16384; > > It sure is. > > This is going to cause an 9000-byte MTU to use a 16384-byte allocation. > e1000_alloc_rx_buffers() adds two bytes to that, so we do kmalloc(16386), > which causes the slab allocator to request 32768 bytes. All for a 9kbyte skb. I wonder if we can't account for NET_IP_ALIGN when selecting bufsize, to get at rid of at least 1 order size before we netdev_alloc_skb. This should make 9k frames only kmalloc(16384) and thus stay within the 16k boundary. I hope. Completely untested: don't commit :) Auke --- e1000: account for NET_IP_ALIGN when calculating bufsiz Account for NET_IP_ALIGN when requesting buffer sizes from netdev_alloc_skb to reduce slab allocation by half. Signed-off-by: Auke Kok diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c index bb0d129..20b1f39 100644 --- a/drivers/net/e1000/e1000_main.c +++ b/drivers/net/e1000/e1000_main.c @@ -1144,7 +1144,7 @@ #endif pci_read_config_word(pdev, PCI_COMMAND, &hw->pci_cmd_word); - adapter->rx_buffer_len = MAXIMUM_ETHERNET_VLAN_SIZE; + adapter->rx_buffer_len = MAXIMUM_ETHERNET_VLAN_SIZE + NET_IP_ALIGN; adapter->rx_ps_bsize0 = E1000_RXBUFFER_128; hw->max_frame_size = netdev->mtu + ENET_HEADER_SIZE + ETHERNET_FCS_SIZE; @@ -3234,26 +3234,27 @@ #define MAX_STD_JUMBO_FRAME_SIZE 9234 * larger slab size * i.e. RXBUFFER_2048 --> size-4096 slab */ - if (max_frame <= E1000_RXBUFFER_256) + if (max_frame + NET_IP_ALIGN <= E1000_RXBUFFER_256) adapter->rx_buffer_len = E1000_RXBUFFER_256; - else if (max_frame <= E1000_RXBUFFER_512) + else if (max_frame + NET_IP_ALIGN <= E1000_RXBUFFER_512) adapter->rx_buffer_len = E1000_RXBUFFER_512; - else if (max_frame <= E1000_RXBUFFER_1024) + else if (max_frame + NET_IP_ALIGN <= E1000_RXBUFFER_1024) adapter->rx_buffer_len = E1000_RXBUFFER_1024; - else if (max_frame <= E1000_RXBUFFER_2048) + else if (max_frame + NET_IP_ALIGN <= E1000_RXBUFFER_2048) adapter->rx_buffer_len = E1000_RXBUFFER_2048; - else if (max_frame <= E1000_RXBUFFER_4096) + else if (max_frame + NET_IP_ALIGN <= E1000_RXBUFFER_4096) adapter->rx_buffer_len = E1000_RXBUFFER_4096; - else if (max_frame <= E1000_RXBUFFER_8192) + else if (max_frame + NET_IP_ALIGN <= E1000_RXBUFFER_8192) adapter->rx_buffer_len = E1000_RXBUFFER_8192; - else if (max_frame <= E1000_RXBUFFER_16384) + else adapter->rx_buffer_len = E1000_RXBUFFER_16384; /* adjust allocation if LPE protects us, and we aren't using SBP */ if (!adapter->hw.tbi_compatibility_on && ((max_frame == MAXIMUM_ETHERNET_FRAME_SIZE) || (max_frame == MAXIMUM_ETHERNET_VLAN_SIZE))) - adapter->rx_buffer_len = MAXIMUM_ETHERNET_VLAN_SIZE; + adapter->rx_buffer_len = MAXIMUM_ETHERNET_VLAN_SIZE + + NET_IP_ALIGN; netdev->mtu = new_mtu; @@ -4076,7 +4076,8 @@ e1000_alloc_rx_buffers(struct e1000_adap struct e1000_buffer *buffer_info; struct sk_buff *skb; unsigned int i; - unsigned int bufsz = adapter->rx_buffer_len + NET_IP_ALIGN; + /* we have already accounted for NET_IP_ALIGN */ + unsigned int bufsz = adapter->rx_buffer_len; i = rx_ring->next_to_use; buffer_info = &rx_ring->buffer_info[i]; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/