Commit 925a2421 authored by Dust Li's avatar Dust Li Committed by David S. Miller
Browse files

Revert "net/smc: don't req_notify until all CQEs drained" 

This reverts commit a505cce6.

Leon says:
  We already discussed that. SMC should be changed to use
  RDMA CQ pool API
  drivers/infiniband/core/cq.c.
  ib_poll_handler() has much better implementation (tracing,
  IRQ rescheduling, proper error handling) than this SMC variant.

Since we will switch to ib_poll_handler() in the future,
revert this patch.

Link: https://lore.kernel.org/netdev/20220301105332.GA9417@linux.alibaba.com/


Suggested-by: default avatarLeon Romanovsky <leon@kernel.org>
Suggested-by: default avatarKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: default avatarDust Li <dust.li@linux.alibaba.com>
Reviewed-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d59e3cba

net/smc/smc_wr.c

+21 −28
Original line number Diff line number Diff line
@@ -137,28 +137,25 @@ static void smc_wr_tx_tasklet_fn(struct tasklet_struct *t) 
{

	struct smc_ib_device *dev = from_tasklet(dev, t, send_tasklet);

	struct ib_wc wc[SMC_WR_MAX_POLL_CQE];

	int i, rc;

	int i = 0, rc;

	int polled = 0;



again:

	polled++;

	do {

		memset(&wc, 0, sizeof(wc));

		rc = ib_poll_cq(dev->roce_cq_send, SMC_WR_MAX_POLL_CQE, wc);

		if (polled == 1) {

			ib_req_notify_cq(dev->roce_cq_send,

					 IB_CQ_NEXT_COMP |

					 IB_CQ_REPORT_MISSED_EVENTS);

		}

		if (!rc)

			break;

		for (i = 0; i < rc; i++)

			smc_wr_tx_process_cqe(&wc[i]);

		if (rc < SMC_WR_MAX_POLL_CQE)

			/* If < SMC_WR_MAX_POLL_CQE, the CQ should have been

			 * drained, no need to poll again. --Guangguan Wang

			 */

			break;

	} while (rc > 0);



	/* IB_CQ_REPORT_MISSED_EVENTS make sure if ib_req_notify_cq() returns

	 * 0, it is safe to wait for the next event.

	 * Else we must poll the CQ again to make sure we won't miss any event

	 */

	if (ib_req_notify_cq(dev->roce_cq_send,

			     IB_CQ_NEXT_COMP |

			     IB_CQ_REPORT_MISSED_EVENTS))

	if (polled == 1)

		goto again;

}
@@ -481,28 +478,24 @@ static void smc_wr_rx_tasklet_fn(struct tasklet_struct *t) 
{

	struct smc_ib_device *dev = from_tasklet(dev, t, recv_tasklet);

	struct ib_wc wc[SMC_WR_MAX_POLL_CQE];

	int polled = 0;

	int rc;



again:

	polled++;

	do {

		memset(&wc, 0, sizeof(wc));

		rc = ib_poll_cq(dev->roce_cq_recv, SMC_WR_MAX_POLL_CQE, wc);

		if (rc > 0)

			smc_wr_rx_process_cqes(&wc[0], rc);

		if (rc < SMC_WR_MAX_POLL_CQE)

			/* If < SMC_WR_MAX_POLL_CQE, the CQ should have been

			 * drained, no need to poll again. --Guangguan Wang

			 */

		if (polled == 1) {

			ib_req_notify_cq(dev->roce_cq_recv,

					 IB_CQ_SOLICITED_MASK

					 | IB_CQ_REPORT_MISSED_EVENTS);

		}

		if (!rc)

			break;

		smc_wr_rx_process_cqes(&wc[0], rc);

	} while (rc > 0);



	/* IB_CQ_REPORT_MISSED_EVENTS make sure if ib_req_notify_cq() returns

	 * 0, it is safe to wait for the next event.

	 * Else we must poll the CQ again to make sure we won't miss any event

	 */

	if (ib_req_notify_cq(dev->roce_cq_recv,

			     IB_CQ_SOLICITED_MASK |

			     IB_CQ_REPORT_MISSED_EVENTS))

	if (polled == 1)

		goto again;

}