[openib-general] Re: [PATCH 07/16] ehca: interrupt handling routines

[Shirley Ma]

"Michael S. Tsirkin" <mst at mellanox.co.il> wrote on 05/09/2006 01:20:41 PM:

> Quoting r. Shirley Ma <xma at us.ibm.com>:
> > My understanding is NAPI handle interrutps CQ callbacks on the same 
CPU.
> 
> My understanding is NAPI disables interrupts under high RX load. No?
> 
> -- 
> MST

Yes, NAPI disables the interrupts based on the weight. In IPoIB case, it 
doesn't 
send out the next completion notification under heavy loading. 
The similiar CQ polling is still in NAPI on same CPU, but it's not a 
callback
anymore. 

What I find that the send completion and recv completion are not 
that fast, which means RX load is not that heavy in IPoIB. That might be
the reason compared to multiple threads implementation NAPI is not good.

Thanks
Shirley Ma
IBM Linux Technology Center
15300 SW Koll Parkway
Beaverton, OR 97006-6063
Phone(Fax): (503) 578-7638
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