[asterisk-dev] rtp scalability improvement...

[Sergey Kuznetsov]

Andrew Kohlsmith wrote:
> On Sunday 19 March 2006 20:57, Sergey Kuznetsov wrote:
>   
>> Performance dies not because of system calls, but because 20 000
>> interruptions/sec happened at that moment.
>>     
>
> Uh... gigE NICs typically switch from interrupt mode to polled mode, and 
> almost every modern NIC has the ability to switch from "one interrupt per 
> packet that gets through the MAC filter" to "one interrupt per x packets", 
> which drastically reduces interrupt load (at the cost of some latency).
>   
Andrew,

I know that very well, but still not all of them doing that.
It's implemented mostly in GigE cards, otherwise they dying in IRQ mode. 
And it was introduced right after
Jamal Hadi Salim and Alexei Kuznetsov did the presentation and 
implementation of NAPI in the code.
Even after tg3 chipset was not optimized properly in its hardware 
implementation. And you can see a lot of
tg3 integrated motherboards.
PS: I spent quite a lot of time to shovel Linux network layer and 
network drivers code in the last decade.


All the Best!
Sergey.