Re: Problem in pfmemalloc skb handling in net/core/dev.c

Mel Gorman
2021-04-09T07:30:52Z

On Thu, Apr 08, 2021 at 11:52:01AM -0700, Xie He wrote:
> Hi Mel Gorman,
>
> I may have found a problem in pfmemalloc skb handling in
> net/core/dev.c. I see there are "if" conditions checking for
> "sk_memalloc_socks() && skb_pfmemalloc(skb)", and when the condition
> is true, the skb is handled specially as a pfmemalloc skb, otherwise
> it is handled as a normal skb.
>
> However, if "sk_memalloc_socks()" is false and "skb_pfmemalloc(skb)"
> is true, the skb is still handled as a normal skb. Is this correct?

Under what circumstances do you expect sk_memalloc_socks() to be false
and skb_pfmemalloc() to be true that would cause a problem?

--
Mel Gorman
SUSE Labs