Commit 561b58b6 authored by Changpeng Liu's avatar Changpeng Liu Committed by Tomasz Zawadzki
Browse files

lib/ublk: optimize IO resubmission path 



We don't need to allocate data buffer again for the ENOMEM case.

Change-Id: I047ae76bedd18efa04357e348d013ba3956e7b18
Signed-off-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/18789


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarKonrad Sztyber <konrad.sztyber@intel.com>
parent 5f6519d1

lib/ublk/ublk.c

+30 −28
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ static struct spdk_cpuset g_core_mask; 
struct ublk_queue;

struct ublk_poll_group;

struct ublk_io;

static void ublk_submit_bdev_io(struct ublk_queue *q, struct ublk_io *io);

static void _ublk_submit_bdev_io(struct ublk_queue *q, struct ublk_io *io);

static void ublk_dev_queue_fini(struct ublk_queue *q);

static int ublk_poll(void *arg);

static int ublk_ctrl_cmd(struct spdk_ublk_dev *ublk, uint32_t cmd_op);
@@ -970,7 +970,7 @@ ublk_resubmit_io(void *arg) 
{

	struct ublk_io *io = (struct ublk_io *)arg;



	ublk_submit_bdev_io(io->q, io);

	_ublk_submit_bdev_io(io->q, io);

}



static void
@@ -997,6 +997,7 @@ ublk_io_get_buffer_cb(struct spdk_iobuf_entry *iobuf, void *buf) 
	struct ublk_io *io = SPDK_CONTAINEROF(iobuf, struct ublk_io, iobuf);



	io->mpool_entry = buf;

	assert(io->payload == NULL);

	io->payload = (void *)(uintptr_t)SPDK_ALIGN_CEIL((uintptr_t)buf, 4096ULL);

	io->get_buf_cb(io);

}
@@ -1030,34 +1031,11 @@ ublk_io_put_buffer(struct ublk_io *io, struct spdk_iobuf_channel *iobuf_ch) 
}



static void

read_get_buffer_done(struct ublk_io *io)

{

	struct spdk_bdev_desc *desc = io->bdev_desc;

	struct spdk_io_channel *ch = io->bdev_ch;

	uint64_t offset_blocks, num_blocks;

	int rc = 0;

	const struct ublksrv_io_desc *iod = io->iod;



	offset_blocks = iod->start_sector >> io->sector_per_block_shift;

	num_blocks = iod->nr_sectors >> io->sector_per_block_shift;



	rc = spdk_bdev_read_blocks(desc, ch, io->payload, offset_blocks, num_blocks, ublk_io_done, io);

	if (rc == -ENOMEM) {

		SPDK_INFOLOG(ublk, "No memory, start to queue io.\n");

		ublk_queue_io(io);

	} else if (rc < 0) {

		SPDK_ERRLOG("ublk io failed in ublk_queue_io, rc=%d.\n", rc);

		ublk_io_done(NULL, false, io);

	}

}



static void

ublk_submit_bdev_io(struct ublk_queue *q, struct ublk_io *io)

_ublk_submit_bdev_io(struct ublk_queue *q, struct ublk_io *io)

{

	struct spdk_ublk_dev *ublk = q->dev;

	struct spdk_bdev_desc *desc = io->bdev_desc;

	struct spdk_io_channel *ch = io->bdev_ch;

	struct spdk_iobuf_channel *iobuf_ch = &q->poll_group->iobuf_ch;

	uint64_t offset_blocks, num_blocks;

	uint8_t ublk_op;

	int rc = 0;
@@ -1070,8 +1048,8 @@ ublk_submit_bdev_io(struct ublk_queue *q, struct ublk_io *io) 
	io->result = num_blocks * spdk_bdev_get_data_block_size(ublk->bdev);

	switch (ublk_op) {

	case UBLK_IO_OP_READ:

		ublk_io_get_buffer(io, iobuf_ch, read_get_buffer_done);

		return;

		rc = spdk_bdev_read_blocks(desc, ch, io->payload, offset_blocks, num_blocks, ublk_io_done, io);

		break;

	case UBLK_IO_OP_WRITE:

		assert((void *)iod->addr == io->payload);

		rc = spdk_bdev_write_blocks(desc, ch, io->payload, offset_blocks, num_blocks, ublk_io_done, io);
@@ -1100,6 +1078,30 @@ ublk_submit_bdev_io(struct ublk_queue *q, struct ublk_io *io) 
	}

}



static void

read_get_buffer_done(struct ublk_io *io)

{

	_ublk_submit_bdev_io(io->q, io);

}



static void

ublk_submit_bdev_io(struct ublk_queue *q, struct ublk_io *io)

{

	struct spdk_iobuf_channel *iobuf_ch = &q->poll_group->iobuf_ch;

	const struct ublksrv_io_desc *iod = io->iod;

	uint8_t ublk_op;



	ublk_op = ublksrv_get_op(iod);

	switch (ublk_op) {

	case UBLK_IO_OP_READ:

		ublk_io_get_buffer(io, iobuf_ch, read_get_buffer_done);

		break;

	default:

		_ublk_submit_bdev_io(q, io);

		break;

	}

}



static inline void

ublksrv_queue_io_cmd(struct ublk_queue *q,

		     struct ublk_io *io, unsigned tag)