Commit 49564357 authored Dec 13, 2020 by Shuhei Matsumoto Committed by Tomasz Zawadzki Dec 15, 2020

bdev/nvme: Call bdev_nvme_readv() directly when buffer is already allocated



bdev_nvme_submit_request() calls bdev_nvme_get_buf_cb() directly
when the buffer is already allocated. This is for performance improvement
but will be helpful for the upcoming multipath feature to retry
read I/O submission because buffer should be allocated only once.

By reading the code a little more critically, bdev_nvme_submit_request()
can call bdev_nvme_readv() directly in this case, and do in this patch.

Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: I005c70deabf7fbfe84b7029e9ef103ae122605e1
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/5558


Community-CI: Broadcom CI
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>

parent 2b9daef6

module/bdev/nvme/bdev_nvme.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -642,12 +642,20 @@ _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);
		return bdev_nvme_readv(nbdev->nvme_ns->ns,
		nvme_ch->qpair,
		nbdev_io,
		bdev_io->u.bdev.iovs,
		bdev_io->u.bdev.iovcnt,
		bdev_io->u.bdev.md_buf,
		bdev_io->u.bdev.num_blocks,
		bdev_io->u.bdev.offset_blocks,
		bdev->dif_check_flags);
		} else {
		spdk_bdev_io_get_buf(bdev_io, bdev_nvme_get_buf_cb,
		bdev_io->u.bdev.num_blocks * bdev->blocklen);
		}
		return 0;
		}

		case SPDK_BDEV_IO_TYPE_WRITE:
		return bdev_nvme_writev(nbdev->nvme_ns->ns,