Messages in this thread | | | Date | Thu, 25 Jan 2007 20:21:01 -0500 | From | Jeff Garzik <> | Subject | Re: [patch] scsi: use lock per host instead of per device for shared queue tag host |
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Ed Lin wrote: > There may possibly be some other errors. So we need a lock here. > I think the simple but reliable way to do it is just to replace > queue lock with a host lock. James pointed out that there may be > performance slow down when many devices are accessed at the > same time. But I think the major part is still on the hardware, > and a host lock is the price these kind of controllers must pay.
I agree.
Further, a host lock is (a) common across many controllers, to protect host-wide resources and (b) only limits us when the controller is CPU-limited, a very rare scenario.
Jeff
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