2022-04-18 14:14 GMT+09:00, Hyunchul Lee <hyc.lee@xxxxxxxxx>:
> SMB2_READ/SMB2_WRITE request has to be granted the number
> of rw credits, the pages the request wants to transfer
> / the maximum pages which can be registered with one
> MR to read and write a file.
> And allocate enough RDMA resources for the maximum
> number of rw credits allowed by ksmbd.
>
> Signed-off-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>
> ---
> changes from v2:
> - Split a v2 patch to 4 patches.
>
> fs/ksmbd/transport_rdma.c | 120 +++++++++++++++++++++++---------------
> 1 file changed, 72 insertions(+), 48 deletions(-)
>
> diff --git a/fs/ksmbd/transport_rdma.c b/fs/ksmbd/transport_rdma.c
> index 5e34625b5faf..895600cc8c5d 100644
> --- a/fs/ksmbd/transport_rdma.c
> +++ b/fs/ksmbd/transport_rdma.c
> @@ -80,9 +80,9 @@ static int smb_direct_max_fragmented_recv_size = 1024 *
> 1024;
> /* The maximum single-message size which can be received */
> static int smb_direct_max_receive_size = 8192;
>
> -static int smb_direct_max_read_write_size = 524224;
> +static int smb_direct_max_read_write_size = 8 * 1024 * 1024;
>
> -static int smb_direct_max_outstanding_rw_ops = 8;
> +static int smb_direct_outstanding_max_read_write = 1;
this variable is neeeded ?
>
> static LIST_HEAD(smb_direct_device_list);
> static DEFINE_RWLOCK(smb_direct_device_lock);
> @@ -147,10 +147,12 @@ struct smb_direct_transport {
> atomic_t send_credits;
> spinlock_t lock_new_recv_credits;
> int new_recv_credits;
> - atomic_t rw_avail_ops;
> + int max_rw_credits;
> + int pages_per_rw_credit;
> + atomic_t rw_credits;
>
> wait_queue_head_t wait_send_credits;
> - wait_queue_head_t wait_rw_avail_ops;
> + wait_queue_head_t wait_rw_credits;
>
> mempool_t *sendmsg_mempool;
> struct kmem_cache *sendmsg_cache;
> @@ -377,7 +379,7 @@ static struct smb_direct_transport
> *alloc_transport(struct rdma_cm_id *cm_id)
> t->reassembly_queue_length = 0;
> init_waitqueue_head(&t->wait_reassembly_queue);
> init_waitqueue_head(&t->wait_send_credits);
> - init_waitqueue_head(&t->wait_rw_avail_ops);
> + init_waitqueue_head(&t->wait_rw_credits);
>
> spin_lock_init(&t->receive_credit_lock);
> spin_lock_init(&t->recvmsg_queue_lock);
> @@ -983,18 +985,19 @@ static int smb_direct_flush_send_list(struct
> smb_direct_transport *t,
> }
>
> static int wait_for_credits(struct smb_direct_transport *t,
> - wait_queue_head_t *waitq, atomic_t *credits)
> + wait_queue_head_t *waitq, atomic_t *total_credits,
> + int needed)
> {
> int ret;
>
> do {
> - if (atomic_dec_return(credits) >= 0)
> + if (atomic_sub_return(needed, total_credits) >= 0)
> return 0;
>
> - atomic_inc(credits);
> + atomic_add(needed, total_credits);
> ret = wait_event_interruptible(*waitq,
> - atomic_read(credits) > 0 ||
> - t->status != SMB_DIRECT_CS_CONNECTED);
> + atomic_read(total_credits) >= needed ||
> + t->status != SMB_DIRECT_CS_CONNECTED);
>
> if (t->status != SMB_DIRECT_CS_CONNECTED)
> return -ENOTCONN;
> @@ -1015,7 +1018,19 @@ static int wait_for_send_credits(struct
> smb_direct_transport *t,
> return ret;
> }
>
> - return wait_for_credits(t, &t->wait_send_credits, &t->send_credits);
> + return wait_for_credits(t, &t->wait_send_credits, &t->send_credits, 1);
> +}
> +
> +static int wait_for_rw_credits(struct smb_direct_transport *t, int
> credits)
> +{
> + return wait_for_credits(t, &t->wait_rw_credits, &t->rw_credits, credits);
> +}
> +
> +static int calc_rw_credits(struct smb_direct_transport *t,
> + char *buf, unsigned int len)
> +{
> + return DIV_ROUND_UP(get_buf_page_count(buf, len),
> + t->pages_per_rw_credit);
> }
>
> static int smb_direct_create_header(struct smb_direct_transport *t,
> @@ -1331,8 +1346,8 @@ static void read_write_done(struct ib_cq *cq, struct
> ib_wc *wc,
> smb_direct_disconnect_rdma_connection(t);
> }
>
> - if (atomic_inc_return(&t->rw_avail_ops) > 0)
> - wake_up(&t->wait_rw_avail_ops);
> + if (atomic_inc_return(&t->rw_credits) > 0)
> + wake_up(&t->wait_rw_credits);
>
> rdma_rw_ctx_destroy(&msg->rw_ctx, t->qp, t->qp->port,
> msg->sg_list, msg->sgt.nents, dir);
> @@ -1363,8 +1378,10 @@ static int smb_direct_rdma_xmit(struct
> smb_direct_transport *t,
> struct ib_send_wr *first_wr = NULL;
> u32 remote_key = le32_to_cpu(desc[0].token);
> u64 remote_offset = le64_to_cpu(desc[0].offset);
> + int credits_needed;
>
> - ret = wait_for_credits(t, &t->wait_rw_avail_ops, &t->rw_avail_ops);
> + credits_needed = calc_rw_credits(t, buf, buf_len);
> + ret = wait_for_rw_credits(t, credits_needed);
> if (ret < 0)
> return ret;
>
> @@ -1372,7 +1389,7 @@ static int smb_direct_rdma_xmit(struct
> smb_direct_transport *t,
> msg = kmalloc(offsetof(struct smb_direct_rdma_rw_msg, sg_list) +
> sizeof(struct scatterlist) * SG_CHUNK_SIZE, GFP_KERNEL);
> if (!msg) {
> - atomic_inc(&t->rw_avail_ops);
> + atomic_add(credits_needed, &t->rw_credits);
> return -ENOMEM;
> }
>
> @@ -1381,7 +1398,7 @@ static int smb_direct_rdma_xmit(struct
> smb_direct_transport *t,
> get_buf_page_count(buf, buf_len),
> msg->sg_list, SG_CHUNK_SIZE);
> if (ret) {
> - atomic_inc(&t->rw_avail_ops);
> + atomic_add(credits_needed, &t->rw_credits);
> kfree(msg);
> return -ENOMEM;
> }
> @@ -1417,7 +1434,7 @@ static int smb_direct_rdma_xmit(struct
> smb_direct_transport *t,
> return 0;
>
> err:
> - atomic_inc(&t->rw_avail_ops);
> + atomic_add(credits_needed, &t->rw_credits);
> if (first_wr)
> rdma_rw_ctx_destroy(&msg->rw_ctx, t->qp, t->qp->port,
> msg->sg_list, msg->sgt.nents,
> @@ -1642,11 +1659,19 @@ static int smb_direct_prepare_negotiation(struct
> smb_direct_transport *t)
> return ret;
> }
>
> +static unsigned int smb_direct_get_max_fr_pages(struct smb_direct_transport
> *t)
> +{
> + return min_t(unsigned int,
> + t->cm_id->device->attrs.max_fast_reg_page_list_len,
> + 256);
Why is its max of 256 ?
> +}
> +
> static int smb_direct_init_params(struct smb_direct_transport *t,
> struct ib_qp_cap *cap)
> {
> struct ib_device *device = t->cm_id->device;
> - int max_send_sges, max_pages, max_rw_wrs, max_send_wrs;
> + int max_send_sges, max_rw_wrs, max_send_wrs;
> + unsigned int max_sge_per_wr, wrs_per_credit;
>
> /* need 2 more sge. because a SMB_DIRECT header will be mapped,
> * and maybe a send buffer could be not page aligned.
> @@ -1658,25 +1683,31 @@ static int smb_direct_init_params(struct
> smb_direct_transport *t,
> return -EINVAL;
> }
>
> - /*
> - * allow smb_direct_max_outstanding_rw_ops of in-flight RDMA
> - * read/writes. HCA guarantees at least max_send_sge of sges for
> - * a RDMA read/write work request, and if memory registration is used,
> - * we need reg_mr, local_inv wrs for each read/write.
> + /* Calculate the number of work requests for RDMA R/W.
> + * The maximum number of pages which can be registered
> + * with one Memory region can be transferred with one
> + * R/W credit. And at least 4 work requests for each credit
> + * are needed for MR registration, RDMA R/W, local & remote
> + * MR invalidation.
> */
> t->max_rdma_rw_size = smb_direct_max_read_write_size;
> - max_pages = DIV_ROUND_UP(t->max_rdma_rw_size, PAGE_SIZE) + 1;
> - max_rw_wrs = DIV_ROUND_UP(max_pages, SMB_DIRECT_MAX_SEND_SGES);
> - max_rw_wrs += rdma_rw_mr_factor(device, t->cm_id->port_num,
> - max_pages) * 2;
> - max_rw_wrs *= smb_direct_max_outstanding_rw_ops;
> + t->pages_per_rw_credit = smb_direct_get_max_fr_pages(t);
> + t->max_rw_credits = smb_direct_outstanding_max_read_write *
> + DIV_ROUND_UP(t->max_rdma_rw_size,
> + (t->pages_per_rw_credit - 1) * PAGE_SIZE);
> +
> + max_sge_per_wr = min_t(unsigned int, device->attrs.max_send_sge,
> + device->attrs.max_sge_rd);
> + wrs_per_credit = max_t(unsigned int, 4,
> + DIV_ROUND_UP(t->pages_per_rw_credit,
> + max_sge_per_wr) + 1);
> + max_rw_wrs = t->max_rw_credits * wrs_per_credit;
>
> max_send_wrs = smb_direct_send_credit_target + max_rw_wrs;
> if (max_send_wrs > device->attrs.max_cqe ||
> max_send_wrs > device->attrs.max_qp_wr) {
> - pr_err("consider lowering send_credit_target = %d, or
> max_outstanding_rw_ops = %d\n",
> - smb_direct_send_credit_target,
> - smb_direct_max_outstanding_rw_ops);
> + pr_err("consider lowering send_credit_target = %d\n",
> + smb_direct_send_credit_target);
> pr_err("Possible CQE overrun, device reporting max_cqe %d max_qp_wr
> %d\n",
> device->attrs.max_cqe, device->attrs.max_qp_wr);
> return -EINVAL;
> @@ -1711,7 +1742,7 @@ static int smb_direct_init_params(struct
> smb_direct_transport *t,
>
> t->send_credit_target = smb_direct_send_credit_target;
> atomic_set(&t->send_credits, 0);
> - atomic_set(&t->rw_avail_ops, smb_direct_max_outstanding_rw_ops);
> + atomic_set(&t->rw_credits, t->max_rw_credits);
>
> t->max_send_size = smb_direct_max_send_size;
> t->max_recv_size = smb_direct_max_receive_size;
> @@ -1719,12 +1750,10 @@ static int smb_direct_init_params(struct
> smb_direct_transport *t,
>
> cap->max_send_wr = max_send_wrs;
> cap->max_recv_wr = t->recv_credit_max;
> - cap->max_send_sge = SMB_DIRECT_MAX_SEND_SGES;
> + cap->max_send_sge = max_sge_per_wr;
> cap->max_recv_sge = SMB_DIRECT_MAX_RECV_SGES;
Again, Is there no need to set this value to a value supported by the device?
e.g. device->attrs.max_read_sge
> cap->max_inline_data = 0;
> - cap->max_rdma_ctxs =
> - rdma_rw_mr_factor(device, t->cm_id->port_num, max_pages) *
> - smb_direct_max_outstanding_rw_ops;
> + cap->max_rdma_ctxs = t->max_rw_credits;
> return 0;
> }
>
> @@ -1817,7 +1846,8 @@ static int smb_direct_create_qpair(struct
> smb_direct_transport *t,
> }
>
> t->send_cq = ib_alloc_cq(t->cm_id->device, t,
> - t->send_credit_target, 0, IB_POLL_WORKQUEUE);
> + smb_direct_send_credit_target + cap->max_rdma_ctxs,
> + 0, IB_POLL_WORKQUEUE);
> if (IS_ERR(t->send_cq)) {
> pr_err("Can't create RDMA send CQ\n");
> ret = PTR_ERR(t->send_cq);
> @@ -1826,8 +1856,7 @@ static int smb_direct_create_qpair(struct
> smb_direct_transport *t,
> }
>
> t->recv_cq = ib_alloc_cq(t->cm_id->device, t,
> - cap->max_send_wr + cap->max_rdma_ctxs,
> - 0, IB_POLL_WORKQUEUE);
> + t->recv_credit_max, 0, IB_POLL_WORKQUEUE);
> if (IS_ERR(t->recv_cq)) {
> pr_err("Can't create RDMA recv CQ\n");
> ret = PTR_ERR(t->recv_cq);
> @@ -1856,17 +1885,12 @@ static int smb_direct_create_qpair(struct
> smb_direct_transport *t,
>
> pages_per_rw = DIV_ROUND_UP(t->max_rdma_rw_size, PAGE_SIZE) + 1;
> if (pages_per_rw > t->cm_id->device->attrs.max_sgl_rd) {
> - int pages_per_mr, mr_count;
> -
> - pages_per_mr = min_t(int, pages_per_rw,
> - t->cm_id->device->attrs.max_fast_reg_page_list_len);
> - mr_count = DIV_ROUND_UP(pages_per_rw, pages_per_mr) *
> - atomic_read(&t->rw_avail_ops);
> - ret = ib_mr_pool_init(t->qp, &t->qp->rdma_mrs, mr_count,
> - IB_MR_TYPE_MEM_REG, pages_per_mr, 0);
> + ret = ib_mr_pool_init(t->qp, &t->qp->rdma_mrs,
> + t->max_rw_credits, IB_MR_TYPE_MEM_REG,
> + t->pages_per_rw_credit, 0);
> if (ret) {
> pr_err("failed to init mr pool count %d pages %d\n",
> - mr_count, pages_per_mr);
> + t->max_rw_credits, t->pages_per_rw_credit);
> goto err;
> }
> }
> --
> 2.25.1
>
>
