Commit acfb968a authored by Jim Harris's avatar Jim Harris Committed by Tomasz Zawadzki
Browse files

bdev/nvme: avoid spdk_bdev_io_get_buf call when possible 



The bdev layer nicely handles the case where we call this
function with the buffers already present - it just
immediately calls the get_buf_cb.  But this adds extra
overhead in the case where the buffer is already present.
Since nvme has no alignment restrictions, we can just
check the iovs directly and avoid the extra call to
spdk_bdev_io_get_buf when possible.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I66df0fde574a35e995a3432999d75bdbf9b27212
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/4317


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Broadcom CI
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarTomasz Zawadzki <tomasz.zawadzki@intel.com>
parent c1bfc564

module/bdev/nvme/bdev_nvme.c

+6 −2
Original line number Diff line number Diff line
@@ -574,8 +574,12 @@ _bdev_nvme_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_ 


	switch (bdev_io->type) {

	case SPDK_BDEV_IO_TYPE_READ:

		if (bdev_io->u.bdev.iovs && bdev_io->u.bdev.iovs[0].iov_base) {

			bdev_nvme_get_buf_cb(ch, bdev_io, true);

		} else {

			spdk_bdev_io_get_buf(bdev_io, bdev_nvme_get_buf_cb,

					     bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen);

		}

		return 0;



	case SPDK_BDEV_IO_TYPE_WRITE: