Re: [PATCH net-next 17/20] tcp: defer skb freeing after socket lock is released

On Tue, Nov 16, 2021 at 6:27 AM Jakub Kicinski [off-list ref] wrote:

On Mon, 15 Nov 2021 11:02:46 -0800 Eric Dumazet wrote:

quoted

One cpu can now be fully utilized for the kernel->user copy,
and another cpu is handling BH processing and skb/page
allocs/frees (assuming RFS is not forcing use of a single CPU)

Are you saying the kernel->user copy is not under the socket lock
today? I'm working on getting the crypto & copy from under the socket
lock for ktls, and it looked like tcp does the copy under the lock.

Copy is done currently with socket lock owned.

But each skb is freed one at a time, after its payload has been consumed.

Note that I am also working on performing the copy while still allowing BH
to process incoming packets.

This is a bit more complex, but I think it is doable.