2023-07-03 17:24:13

by Eric Dumazet

[permalink] [raw]
Subject: Re: Memory providers multiplexing (Was: [PATCH net-next v4 4/5] page_pool: remove PP_FLAG_PAGE_FRAG flag)

On Mon, Jul 3, 2023 at 4:45 PM David Ahern <[email protected]> wrote:

> That is my expectation. The tcpdump is just an easy example of accessing
> the skb page frags. skb_copy_and_csum_bits used by icmp is another
> example that can walk frags wanting access to device memory. You did not
> cause a panic or trip a WARN_ON for example with the tcpdump?
>

ICMP packets do not land on the queues having devmem buffers, for
obvious reasons.

Only chosen TCP flows are steered to these queues.