Subject: Re: [PATCH v2 net-next] net: poll/select low latency socket support

From: Eliezer Tamir <[email-masked]>
Date: Tue, 18 Jun 2013 17:50:44 +0300

On 18/06/2013 17:45, Eliezer Tamir wrote:
> On 18/06/2013 17:35, Eric Dumazet wrote:
>> On Tue, 2013-06-18 at 16:25 +0300, Eliezer Tamir wrote:
>>
>>> One other thing,
>>> sock_poll() will only ll_poll if the flag was set _and_ the socket has a
>>> none-zero value in sk->sk_ll_usec so you still only poll on sockets
>>> that were enabled for LLS, not on every socket.
>>
>> But sockets are default enabled for LLS.
>>
>> sock_init_data()
>> {
>>     ...
>>     sk->sk_ll_usec      =   sysctl_net_ll_poll;
>>     ...
>> }
>
> Yes, if you want to globally enable.
>
> But now that we have the socket option, you can leave the global
> setting at 0 and only enable specific sockets via the socket option.
> (I have tested this with a modified sockperf and it works.)

I missed something, you need sysctl_net_ll_poll to be non-zero
for poll to even try.

So maybe add another sysctl value for poll?
maybe sysctl_net_ll_poll for poll
and sysctl_net_ll_read for socket reads?