Messages in this thread Patch in this message | | | Date | Fri, 22 Sep 2006 10:10:36 -0700 | From | Auke Kok <> | Subject | Re: 2.6.1[78] page allocation failure. order:3, mode:0x20 |
| |
Andrew Morton wrote: > On Fri, 22 Sep 2006 07:27:18 +0000 (GMT) > Holger Kiehl <Holger.Kiehl@dwd.de> 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: <IRQ> [<ffffffff8024e516>] __alloc_pages+0x282/0x29b >> Sep 21 21:03:15 athena kernel: [<ffffffff8807aa93>] :ip_tables:ipt_do_table+0x1eb/0x318 >> Sep 21 21:03:15 athena kernel: [<ffffffff8026614b>] cache_grow+0x134/0x33d >> Sep 21 21:03:15 athena kernel: [<ffffffff8026664c>] cache_alloc_refill+0x189/0x1d7 >> Sep 21 21:03:15 athena kernel: [<ffffffff80266724>] __kmalloc+0x8a/0x94 >> Sep 21 21:03:15 athena kernel: [<ffffffff803b5438>] __alloc_skb+0x5c/0x123 >> Sep 21 21:03:15 athena kernel: [<ffffffff803b5f2e>] __netdev_alloc_skb+0x12/0x2d >> Sep 21 21:03:15 athena kernel: [<ffffffff8033cb22>] e1000_alloc_rx_buffers+0x6f/0x2f3 >> Sep 21 21:03:15 athena kernel: [<ffffffff803d1234>] ip_local_deliver+0x173/0x23b >> Sep 21 21:03:15 athena kernel: [<ffffffff8033d29a>] 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 <auke-jan.h.kok@intel.com>
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/
| |