Messages in this thread | | | Date | Sat, 23 Sep 2006 11:50:34 -0700 | From | Auke Kok <> | Subject | Re: 2.6.1[78] page allocation failure. order:3, mode:0x20 |
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Andrew Morton wrote: > On Fri, 22 Sep 2006 22:25:07 -0700 (PDT) > David Miller <davem@davemloft.net> wrote: > >> From: Andrew Morton <akpm@osdl.org> >> Date: Fri, 22 Sep 2006 21:50:00 -0700 >> >>> On Fri, 22 Sep 2006 10:10:36 -0700 >>> Auke Kok <auke-jan.h.kok@intel.com> wrote: >>> >>>> 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. >>> Could we please do whatever is needed to get this blessed and merged? This >>> is such a common problem on such a common driver that I would suggest that >>> we want this in 2.6.18.x as well. At least, I'd expect distributors to >>> ship this fix (they're nuts if they don't) and so it makes sense to deliver >>> it from kernel.org. >> The NET_IP_ALIGN existed not just for fun :) There are ramifications >> for removing it. > > It's still there, isn't it? > > For the 9k MTU case, for example, we end up allocating 16384 byte skbs > instead of 32786 kbytes ones.
yes, the only thing I'm doing is accounting for the 2 bytes one steap earlier. It works fine for the general case and I tested it too, but I am not too sure about the corner cases as the hardware has no notion of mtu at all and could possibly overwrite by two bytes. I think my patch actually give the hardware two bytes too much now, so we're on the other side (safe) of that problem, but I have to verify this first of course.
I'll be wrestling this on monday with Jesse and try to nail it down.
Auke
> > > diff -puN drivers/net/e1000/e1000_main.c~e1000-account-for-net_ip_align-when-calculating-bufsiz drivers/net/e1000/e1000_main.c > --- a/drivers/net/e1000/e1000_main.c~e1000-account-for-net_ip_align-when-calculating-bufsiz > +++ a/drivers/net/e1000/e1000_main.c > @@ -1101,7 +1101,7 @@ e1000_sw_init(struct e1000_adapter *adap > > 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; > @@ -3163,26 +3163,27 @@ e1000_change_mtu(struct net_device *netd > * 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; > > @@ -4002,7 +4003,8 @@ 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/
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