Re: kernel 3.2.27 on arm: WARNING: at mm/page_alloc.c:2109 __alloc_pages_nodemask+0x1d4/0x68c()

Eric Dumazet
2012-10-05T15:04:00Z

On Fri, 2012-10-05 at 16:50 +0200, Maxime Bizon wrote:
> On Fri, 2012-10-05 at 15:02 +0200, Eric Dumazet wrote:
>
> > On Fri, 2012-10-05 at 14:51 +0200, Maxime Bizon wrote:
> >
> > > > New convention would be : pass number of needed bytes after current
> > > > tail, not after current end.
> > >
> > > Fully agree on this
> > >
> >
> > Here is the proposal :
>
> Looks fine
>
> What is your plan for the actual pskb_expand_head() code now that you
> will have absolute values for headroom & tailroom ?
>

They stay relative values.

For example, netlink_trim() really wants to shrink the skb head.

> Because there will still be callers that have no clue of required
> tailroom (nor further headroom requirement), like skb_cow() in
> vlan_reorder_header().
>

What I plan is to not shrink size, unless specifically asked.

Its 3.8 material anyway, so a stable fix is needed on skb_recycle() and
NET_SKB_PAD minimal value.