Re: [tipc-discussion] [net-next v3 1/1] tipc: add smart nagle feature

[Jon M. <jon...@er...>]

Hi Ying,
You're right. I'll fix this. Anyway, I just realized another improvement I could make, so I'll send a new version with both changes.

Regards
///jon


> -----Original Message-----
> From: Ying Xue <yin...@wi...>
> Sent: 29-Oct-19 06:24
> To: Jon Maloy <jon...@er...>; Jon Maloy <ma...@do...>
> Cc: Mohan Krishna Ghanta Krishnamurthy <moh...@er...>;
> par...@gm...; Tung Quang Nguyen <tun...@de...>; Hoang
> Huu Le <hoa...@de...>; Tuong Tong Lien <tuo...@de...>; Gordan
> Mihaljevic <gor...@de...>; tip...@li...
> Subject: Re: [net-next v3 1/1] tipc: add smart nagle feature
> 
> On 10/29/19 1:37 AM, Jon Maloy wrote:
> > @@ -3007,6 +3068,9 @@ static int tipc_setsockopt(struct socket *sock, int lvl, int opt,
> >  	case TIPC_GROUP_LEAVE:
> >  		res = tipc_sk_leave(tsk);
> >  		break;
> > +	case TIPC_NODELAY:
> > +		tsk->nodelay = true;
> > +		break;
> >  	default:
> >  		res = -EINVAL;
> >  	}
> 
> Once user sets tsk->nodelay to true, there is no chance to set it back
> to false. Although this scenario rarely happens for us, it's better that
> we can provide the function.
> 
> For example, below is how TCP supports TCP_NODELAY option:
> 
>         case TCP_NODELAY:
>                 if (val) {
>                         /* TCP_NODELAY is weaker than TCP_CORK, so that
>                          * this option on corked socket is remembered, but
>                          * it is not activated until cork is cleared.
>                          *
>                          * However, when TCP_NODELAY is set we make
>                          * an explicit push, which overrides even TCP_CORK
>                          * for currently queued segments.
>                          */
>                         tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
>                         tcp_push_pending_frames(sk);
>                 } else {
>                         tp->nonagle &= ~TCP_NAGLE_OFF;
>                 }
>                 break;