Thread (23 messages) 23 messages, 3 authors, 2021-09-08

Re: [PATCH 08/10] qla2xxx: Move heart beat handling from dpc thread to workqueue

From: Himanshu Madhani <hidden>
Date: 2021-09-08 14:15:27
Also in: linux-nvme 

On Sep 8, 2021, at 2:28 AM, Nilesh Javali [off-list ref] wrote:

From: Manish Rangankar <mrangankar@marvell.com>

DPC thread gets restricted due to a no-op mailbox, which is a blocking call
and has a high execution frequency. To free up the DPC thread we move no-op
handling to the workqueue. Also, modified qla_do_hb to send no-op MBC if
we don’t have any active interrupts, but there are still IOs outstanding
with firmware.

Fixes: d94d8158e184 ("scsi: qla2xxx: Add heartbeat check")
Cc: stable@vger.kernel.org

quoted hunk ↗ jump to hunk
Signed-off-by: Manish Rangankar <mrangankar@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
---
drivers/scsi/qla2xxx/qla_def.h  |  4 +-
drivers/scsi/qla2xxx/qla_init.c |  2 +
drivers/scsi/qla2xxx/qla_os.c   | 74 +++++++++++++++------------------
3 files changed, 38 insertions(+), 42 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index be2eb75ee1a3..d6e131bf1824 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -3750,6 +3750,7 @@ struct qla_qpair {
	struct qla_fw_resources fwres ____cacheline_aligned;
	u32	cmd_cnt;
	u32	cmd_completion_cnt;
+	u32	prev_completion_cnt;
};

/* Place holder for FW buffer parameters */
@@ -4607,6 +4608,7 @@ struct qla_hw_data {
	struct qla_chip_state_84xx *cs84xx;
	struct isp_operations *isp_ops;
	struct workqueue_struct *wq;
+	struct work_struct hb_work;
Use heartbeat_work (which is not awfully long and reads better.

quoted hunk ↗ jump to hunk
	struct qlfc_fw fw_buf;

	/* FCP_CMND priority support */
@@ -4708,7 +4710,6 @@ struct qla_hw_data {

	struct qla_hw_data_stat stat;
	pci_error_state_t pci_error_state;
-	u64 prev_cmd_cnt;
	struct dma_pool *purex_dma_pool;
	struct btree_head32 host_map;

@@ -4854,7 +4855,6 @@ typedef struct scsi_qla_host {
#define SET_ZIO_THRESHOLD_NEEDED 32
#define ISP_ABORT_TO_ROM	33
#define VPORT_DELETE		34
-#define HEARTBEAT_CHK		38

#define PROCESS_PUREX_IOCB	63

diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index c6b3d0e7489e..a9a4243cb15a 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -7025,12 +7025,14 @@ qla2x00_abort_isp_cleanup(scsi_qla_host_t *vha)
	ha->chip_reset++;
	ha->base_qpair->chip_reset = ha->chip_reset;
	ha->base_qpair->cmd_cnt = ha->base_qpair->cmd_completion_cnt = 0;
+	ha->base_qpair->prev_completion_cnt = 0;
	for (i = 0; i < ha->max_qpairs; i++) {
		if (ha->queue_pair_map[i]) {
			ha->queue_pair_map[i]->chip_reset =
				ha->base_qpair->chip_reset;
			ha->queue_pair_map[i]->cmd_cnt =
			    ha->queue_pair_map[i]->cmd_completion_cnt = 0;
+			ha->base_qpair->prev_completion_cnt = 0;
		}
	}

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index a1e861ecfc01..0454f79a8047 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -2794,6 +2794,16 @@ qla2xxx_scan_finished(struct Scsi_Host *shost, unsigned long time)
	return atomic_read(&vha->loop_state) == LOOP_READY;
}

+static void qla_hb_work_fn(struct work_struct *work)
              ^^^^^^^^^^^^^^
Use qla_heartbeat_work_fn for better readability 

quoted hunk ↗ jump to hunk
+{
+	struct qla_hw_data *ha = container_of(work,
+		struct qla_hw_data, hb_work);
+	struct scsi_qla_host *base_vha = pci_get_drvdata(ha->pdev);
+
+	if (!ha->flags.mbox_busy && base_vha->flags.init_done)
+		qla_no_op_mb(base_vha);
+}
+
static void qla2x00_iocb_work_fn(struct work_struct *work)
{
	struct scsi_qla_host *vha = container_of(work,
@@ -3232,6 +3242,7 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
	    host->transportt, sht->vendor_id);

	INIT_WORK(&base_vha->iocb_work, qla2x00_iocb_work_fn);
+	INIT_WORK(&ha->hb_work, qla_hb_work_fn);

	/* Set up the irqs */
	ret = qla2x00_request_irqs(ha, rsp);
@@ -7118,17 +7129,6 @@ qla2x00_do_dpc(void *data)
			qla2x00_lip_reset(base_vha);
		}

-		if (test_bit(HEARTBEAT_CHK, &base_vha->dpc_flags)) {
-			/*
-			 * if there is a mb in progress then that's
-			 * enough of a check to see if fw is still ticking.
-			 */
-			if (!ha->flags.mbox_busy && base_vha->flags.init_done)
-				qla_no_op_mb(base_vha);
-
-			clear_bit(HEARTBEAT_CHK, &base_vha->dpc_flags);
-		}
-
		ha->dpc_active = 0;
end_loop:
		set_current_state(TASK_INTERRUPTIBLE);
@@ -7187,57 +7187,51 @@ qla2x00_rst_aen(scsi_qla_host_t *vha)

static bool qla_do_heartbeat(struct scsi_qla_host *vha)
{
-	u64 cmd_cnt, prev_cmd_cnt;
-	bool do_hb = false;
	struct qla_hw_data *ha = vha->hw;
-	int i;
+	u32 cmpl_cnt;
+	u16 i;
+	bool do_hb = false;
use do_heartbeat which is self-explanatory and reads better

-	/* if cmds are still pending down in fw, then do hb */
-	if (ha->base_qpair->cmd_cnt != ha->base_qpair->cmd_completion_cnt) {
+	/*
+	 * Allow do_hb only if we don’t have any active interrupts,
+	 * but there are still IOs outstanding with firmware.
+	 */
+	cmpl_cnt = ha->base_qpair->cmd_completion_cnt;
+	if (cmpl_cnt == ha->base_qpair->prev_completion_cnt &&
+	    cmpl_cnt != ha->base_qpair->cmd_cnt) {
		do_hb = true;
		goto skip;
	}
+	ha->base_qpair->prev_completion_cnt = cmpl_cnt;

	for (i = 0; i < ha->max_qpairs; i++) {
-		if (ha->queue_pair_map[i] &&
-		    ha->queue_pair_map[i]->cmd_cnt !=
-		    ha->queue_pair_map[i]->cmd_completion_cnt) {
-			do_hb = true;
-			break;
+		if (ha->queue_pair_map[i]) {
+			cmpl_cnt = ha->queue_pair_map[i]->cmd_completion_cnt;
+			if (cmpl_cnt == ha->queue_pair_map[i]->prev_completion_cnt &&
+			    cmpl_cnt != ha->queue_pair_map[i]->cmd_cnt) {
+				do_hb = true;
+				break;
+			}
+			ha->queue_pair_map[i]->prev_completion_cnt = cmpl_cnt;
		}
	}

skip:
-	prev_cmd_cnt = ha->prev_cmd_cnt;
-	cmd_cnt = ha->base_qpair->cmd_cnt;
-	for (i = 0; i < ha->max_qpairs; i++) {
-		if (ha->queue_pair_map[i])
-			cmd_cnt += ha->queue_pair_map[i]->cmd_cnt;
-	}
-	ha->prev_cmd_cnt = cmd_cnt;
-
-	if (!do_hb && ((cmd_cnt - prev_cmd_cnt) > 50))
-		/*
-		 * IOs are completing before periodic hb check.
-		 * IOs seems to be running, do hb for sanity check.
-		 */
-		do_hb = true;
-
	return do_hb;
}

static void qla_heart_beat(struct scsi_qla_host *vha)
{
+	struct qla_hw_data *ha = vha->hw;
+
	if (vha->vp_idx)
		return;

	if (vha->hw->flags.eeh_busy || qla2x00_chip_is_down(vha))
		return;

-	if (qla_do_heartbeat(vha)) {
-		set_bit(HEARTBEAT_CHK, &vha->dpc_flags);
-		qla2xxx_wake_dpc(vha);
-	}
+	if (qla_do_heartbeat(vha))
+		queue_work(ha->wq, &ha->hb_work);
}

/**************************************************************************
-- 
2.19.0.rc0
--
Himanshu Madhani	 Oracle Linux Engineering

  



    
  

  
    

      

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