Re: DDoS attack causing bad effect on conntrack searches

Eric Dumazet
2010-04-23T09:23:36Z

Le vendredi 23 avril 2010 à 09:55 +0200, Jan Engelhardt a écrit :
> On Friday 2010-04-23 09:46, Eric Dumazet wrote:
> >Years ago, we had to manually change PAGE_OFFSET, and I remember some
> >machines with PAGE_OFFSET 0xA0000000 (1.5 GB LOWMEM),
> >or 0xB0000000 (1.25 GB), (PAE off)
>
> I notice that 0xB0000000, which is now known as LOWMEM_3G_OPT,
> is only available when PAE is off. Would you know the reason for
> that decision? Are some values unsuitable for PAE?
>

If PAE was on, PAGE_OFFSET must be a 1GB multiple.
This is because of hardware limitations.