RE: Avoiding deadlock in iSCSI

[Michael Krause <krause@cup.hp.com>]

At 09:44 PM 9/16/00 -0700, Prasenjit Sarkar/Almaden/IBM wrote:


>Actually, because of interrupt coalescing in Gigabit Ethernet adapters, 
>you can have potentially close many SCSI transactions with one interrupt.
>
>However, you have hit the nail on the head, parallelism tends to (I'm not 
>saying will always) increase the average number of interrupts per 
>transaction if the parallelism decreases the possibility of interrupt 
>coalescing.
>
>And since interrupt coalescing is a statically determined parameter (in 
>current implementations), getting speedups out of parallelism is harder 
>than it appears.

Interrupt management and parallelism are critical to actual application 
throughput.  There are existing solutions that allow throughput to be 
achieved with intelligent interrupt management.  I do not believe iSCSI 
changes anything along these lines and consider this issue to be 
implementation specific.

Mike