Re: 3.7.8/amd64 full interrupt hangs due to iwlwifi under big nfs copies out

Eric Dumazet
2013-02-19T16:21:53Z

On Tue, 2013-02-19 at 11:03 +0100, Johannes Berg wrote:
> On Mon, 2013-02-18 at 21:17 -0800, Eric Dumazet wrote:
>
> > > chrome: page allocation failure: order:1, mode:0x4020
> > > Pid: 8730, comm: chrome Tainted: G O 3.7.8-amd64-preempt-20121226-fixwd #1
> > > Call Trace:
> > > <IRQ> [<ffffffff810d5f38>] warn_alloc_failed+0x117/0x12c
>
> > You could try to load iwlwifi with amsdu_size_8K set to 0 (disable)
> >
> > It should hopefully use order-0 pages
>
> It will, do that then, unfortunately it can't switch at runtime because
> it advertised this support to the access point or clients.

What are the drawbacks of setting amsdu_size_8K to 0 by default ?

Alternative would be :

- As long as we cant allocate order-1 pages (to refill the RX ring),
copy incoming frames into order-0 pages, so that order-1 pages are still
available for the NIC.