Commit bb0f5445 authored by Kevin Barnett's avatar Kevin Barnett Committed by Martin K. Petersen
Browse files

scsi: smartpqi: Improve accuracy/performance of raid-bypass-counter 



The original implementation of this counter used an atomic variable.
However, this implementation negatively impacted performance in some
configurations.

Switch to using per_cpu variables.

Reviewed-by: default avatarScott Benesh <scott.benesh@microchip.com>
Reviewed-by: default avatarScott Teel <scott.teel@microchip.com>
Reviewed-by: default avatarMike McGowen <mike.mcgowen@microchip.com>
Co-developed-by: default avatarMahesh Rajashekhara <mahesh.rajashekhara@microchip.com>
Signed-off-by: default avatarMahesh Rajashekhara <mahesh.rajashekhara@microchip.com>
Signed-off-by: default avatarKevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: default avatarDon Brace <don.brace@microchip.com>
Link: https://lore.kernel.org/r/20240711194704.982400-3-don.brace@microchip.com


Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 0e21e733

drivers/scsi/smartpqi/smartpqi.h

+1 −1
Original line number Diff line number Diff line
@@ -1158,7 +1158,7 @@ struct pqi_scsi_dev { 


	struct pqi_stream_data stream_data[NUM_STREAMS_PER_LUN];

	atomic_t scsi_cmds_outstanding[PQI_MAX_LUNS_PER_DEVICE];

	unsigned int raid_bypass_cnt;

	u64 __percpu *raid_bypass_cnt;



	struct pqi_tmf_work tmf_work[PQI_MAX_LUNS_PER_DEVICE];

};

drivers/scsi/smartpqi/smartpqi_init.c

+26 −4
Original line number Diff line number Diff line
@@ -1508,6 +1508,12 @@ static int pqi_get_raid_map(struct pqi_ctrl_info *ctrl_info, 
	if (rc)

		goto error;



	device->raid_bypass_cnt = alloc_percpu(u64);

	if (!device->raid_bypass_cnt) {

		rc = -ENOMEM;

		goto error;

	}



	device->raid_map = raid_map;



	return 0;
@@ -2099,6 +2105,10 @@ static void pqi_scsi_update_device(struct pqi_ctrl_info *ctrl_info, 
				/* To prevent this from being freed later. */

				new_device->raid_map = NULL;

			}

			if (new_device->raid_bypass_enabled && existing_device->raid_bypass_cnt == NULL) {

				existing_device->raid_bypass_cnt = new_device->raid_bypass_cnt;

				new_device->raid_bypass_cnt = NULL;

			}

			existing_device->raid_bypass_configured = new_device->raid_bypass_configured;

			existing_device->raid_bypass_enabled = new_device->raid_bypass_enabled;

		}
@@ -2121,6 +2131,7 @@ static void pqi_scsi_update_device(struct pqi_ctrl_info *ctrl_info, 
static inline void pqi_free_device(struct pqi_scsi_dev *device)

{

	if (device) {

		free_percpu(device->raid_bypass_cnt);

		kfree(device->raid_map);

		kfree(device);

	}
@@ -6007,6 +6018,7 @@ static int pqi_scsi_queue_command(struct Scsi_Host *shost, struct scsi_cmnd *scm 
	u16 hw_queue;

	struct pqi_queue_group *queue_group;

	bool raid_bypassed;

	u64 *raid_bypass_cnt;

	u8 lun;



	scmd->host_scribble = PQI_NO_COMPLETION;
@@ -6053,7 +6065,8 @@ static int pqi_scsi_queue_command(struct Scsi_Host *shost, struct scsi_cmnd *scm 
			rc = pqi_raid_bypass_submit_scsi_cmd(ctrl_info, device, scmd, queue_group);

			if (rc == 0 || rc == SCSI_MLQUEUE_HOST_BUSY) {

				raid_bypassed = true;

				device->raid_bypass_cnt++;

				raid_bypass_cnt = per_cpu_ptr(device->raid_bypass_cnt, smp_processor_id());

				(*raid_bypass_cnt)++;

			}

		}

		if (!raid_bypassed)
@@ -7350,7 +7363,9 @@ static ssize_t pqi_raid_bypass_cnt_show(struct device *dev, 
	struct scsi_device *sdev;

	struct pqi_scsi_dev *device;

	unsigned long flags;

	unsigned int raid_bypass_cnt;

	u64 raid_bypass_cnt;

	int cpu;

	u64 *per_cpu_bypass_cnt_ptr;



	sdev = to_scsi_device(dev);

	ctrl_info = shost_to_hba(sdev->host);
@@ -7366,11 +7381,18 @@ static ssize_t pqi_raid_bypass_cnt_show(struct device *dev, 
		return -ENODEV;

	}



	raid_bypass_cnt = device->raid_bypass_cnt;

	raid_bypass_cnt = 0;



	if (device->raid_bypass_cnt) {

		for_each_online_cpu(cpu) {

			per_cpu_bypass_cnt_ptr = per_cpu_ptr(device->raid_bypass_cnt, cpu);

			raid_bypass_cnt += *per_cpu_bypass_cnt_ptr;

		}

	}



	spin_unlock_irqrestore(&ctrl_info->scsi_device_list_lock, flags);



	return scnprintf(buffer, PAGE_SIZE, "0x%x\n", raid_bypass_cnt);

	return scnprintf(buffer, PAGE_SIZE, "0x%llx\n", raid_bypass_cnt);

}



static ssize_t pqi_sas_ncq_prio_enable_show(struct device *dev,