Re: Stack Trace. Bad?

[Evgeniy Polyakov <johnpol@2ka.mipt.ru>]

Hi Jon.

On Tue, Nov 06, 2007 at 02:23:03PM -0600, Jon Nelson (jnelson@jamponi.net) wrote:
> [linux-raid was also emailed this same information]

It looks like it was not :)

> I was testing some network throughput today and ran into this.
> I should note that I've this motherboard has 2x MCP55 Ethernet and one
> of them works fine and the other one gives lots and lots of frame
> errors under load.
> 
> The following is only an harmless informational message.
> Unless you get a _continuous_flood_ of these messages it means
> everything is working fine. Allocations from irqs cannot be
> perfectly reliable and the kernel is designed to handle that.
> md0_raid5: page allocation failure. order:2, mode:0x20
> 
> Call Trace:
>  <IRQ>  [<ffffffff802684c2>] __alloc_pages+0x324/0x33d
>  [<ffffffff80283147>] kmem_getpages+0x66/0x116
>  [<ffffffff8028367a>] fallback_alloc+0x104/0x174
>  [<ffffffff80283330>] kmem_cache_alloc_node+0x9c/0xa8
>  [<ffffffff80396984>] __alloc_skb+0x65/0x138
>  [<ffffffff8821d82a>] :forcedeth:nv_alloc_rx_optimized+0x4d/0x18f

What MTU for this card is? Forcedeth supports jumbo frames, but does it
in very unoptimized way, particulary by relying on the possibility to
allocate 2-order pages, which is wrong.

So, set MTU to 1500 and things will be back into good shape.
I think adding fragments support is not a short-term solution because
of closed specs.

-- 
	Evgeniy Polyakov