Re: [PATCH] net: remove release/lock_sock in tcp_splice_read

[Jason Xing]

On Thu, Aug 15, 2024 at 7:23 PM Paolo Abeni <pabeni@xxxxxxxxxx> wrote:
>
>
>
> On 8/15/24 12:55, Jason Xing wrote:
> > On Thu, Aug 15, 2024 at 6:40 PM Paolo Abeni <pabeni@xxxxxxxxxx> wrote:
> > [...]
> >>> -             release_sock(sk);
> >>> -             lock_sock(sk);
> >>
> >> This is needed to flush the sk backlog.
> >>
> >> Somewhat related, I think we could replace the pair with sk_flush_backlog().
> >>
> >
> > Do you think we could do this like the following commit:
> >
> > commit d41a69f1d390fa3f2546498103cdcd78b30676ff
> > Author: Eric Dumazet <edumazet@xxxxxxxxxx>
> > Date:   Fri Apr 29 14:16:53 2016 -0700
> >
> >      tcp: make tcp_sendmsg() aware of socket backlog
> >
> >      Large sendmsg()/write() hold socket lock for the duration of the call,
> >      unless sk->sk_sndbuf limit is hit. This is bad because incoming packets
> >      are parked into socket backlog for a long time. >
> > ?
>
> Yep. To be more accurate I was looking at commit
> 93afcfd1db35882921b2521a637c78755c27b02c

Thanks. It arouses my interest. Now I do believe we can do such
optimization in this function.

>
> In any case this should be unrelated from the supposed issue.

Sure.

Thanks,
Jason