First, improve packing of spdk_bdev_io. Move any
fields which must be zeroed into the first cacheline.
Also change type and status from enums (needing 4 bytes)
to int16_t which is still a far bigger range than
needed.
Next, modify spdk_bdev_get_io to only zero the
first cacheline (actually a bit less).
SPDK_BDEV_IO_TYPE_INVALID is also added, making it
explicit that 0 is an invalid value for the IO type.
Previously this was somewhat inferred.
There are still additional improvements that can
be made to this area - primarily combining
spdk_bdev_get_io() and spdk_bdev_io_init() into
a single function.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I1916d6d5db02c93622b9725ec1095148e3f384d8
Reviewed-on: https://review.gerrithub.io/377799
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
70a0bc3096