Linus Torvalds wrote:
On Wed, 17 May 2006, Jens Axboe wrote:
Some devices need serialization between them, and the only way to
achieve that currently is by sharing a queue.
Hmm? No. We share the queue for some things, but the most _common_ example
of a device that needs serialization between queues is IDE, and we don't
share queues there. We have independent queues, they just end up sharing
certain infrastructure (tags and locking).
Strongly agreed.
Note that libata uses independent queues, but serializes access to them.
This is the sort of "group of queues" infrastructure I find helpful.
But they _are_ independent, and you can have different elevators,
different merging rules, and even different request functions for the
different queues - even if they also have some things they share.
Yep.
And yes, you can see an ATA host as a host in the SCSI sense, but I wanted
Actually libata presents one Scsi_Host per SATA port on each controller,
FWIW :) So the Scsi_Host notion WRT queues _is_ limiting, which is the
reason why I refer to "group of queues".
Jeff
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