Re: [PATCH] net: No more expensive sock_hold()/sock_put() on each tx

[David Miller <davem@davemloft.net>]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 10 Jun 2009 10:30:49 +0200

> David Miller a écrit :
>> From: Eric Dumazet <eric.dumazet@gmail.com>
>> Date: Thu, 04 Jun 2009 11:18:35 +0200
>> 
>> Eric, I don't understand this part, please enlighten me :-)
>> 
>> Just because we've liberated all of the write buffer space, that does
>> not mean that it's time to kill off the socket completely.
>> 
>> Right?
> 
> Remember we initialize this field to one.
> 
> If we freed all write buffer space, final value is one, not zero.
> 
> res == 0 only if we both freed all write buffer space, *and* socket was
> also refcounted to 0 (sk_free() then realized it could not yet call __sk_free())
> 
> So we cheat a litle bit, because of this offset of one, we might block a sender a litle bit earlier :)

Now I understand, thanks!

Patch applied.