Config #1 remains what is shown as an example in the spec. Change
config #0 to just have 1 work group and 1 work queue all backed
by 4 engines. As the majority of initial use cases will not be
implementing separate priorities and/or different back end
targets (mem, pmem, etc) having just 1 group and work queue makes
the most sense as it allows the silicon to decide which engine to
use.
Also, having multiple work queues spreads out the available
entires such that if we're not using all of the work queues then
we're not using all of the resources. As channels are created
they are assigned the next available device. As a channel is
assigned a device that is already in use it will round robin
work queues. If then, for example, we have 16 devices then only
the first work queue will ever be used for the first 16 threads
which seems and if there are even just 2 work queues per device
it would take 32 threads to use all of the resources at the
device.
By haing just one work queue per device we always have the max
number of work queue entries available regardless of how many threads
are being used.
Signed-off-by: paul luse <paul.e.luse@intel.com>
Change-Id: Ie15ff6bdea12525fe3bfc769613084ddd2de50bf
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/5845
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Reviewed-by: Ziye Yang <ziye.yang@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
15c0e78042