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scsi: smartpqi: Remove contention for raid_bypass_cnt

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Reduce CPU contention when incrementing variable raid_bypass_cnt.

Remove the atomic operations for this variable by changing the atomic to an
unsigned int and replace atomic operations with standard operations. The
value is only checked that it is increasing and accuracy is not required.

Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Scott Teel <scott.teel@microchip.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: Mike McGowen <mike.mcgowen@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Link: https://lore.kernel.org/r/20230428153712.297638-6-don.brace@microchip.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Mike McGowen 2023-04-28 10:37:05 -05:00 committed by Martin K. Petersen
parent 2312e844dc
commit 80d560d94f
2 changed files with 4 additions and 4 deletions
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2
drivers/scsi/smartpqi/smartpqi.h
View File

@ -1147,7 +1147,7 @@ struct pqi_scsi_dev {
struct pqi_stream_data stream_data[NUM_STREAMS_PER_LUN];
atomic_t scsi_cmds_outstanding[PQI_MAX_LUNS_PER_DEVICE];
atomic_t raid_bypass_cnt;
unsigned int raid_bypass_cnt;
};
/* VPD inquiry pages */

6
drivers/scsi/smartpqi/smartpqi_init.c
View File

@ -6052,7 +6052,7 @@ 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;
atomic_inc(&device->raid_bypass_cnt);
device->raid_bypass_cnt++;
}
}
if (!raid_bypassed)
@ -7288,7 +7288,7 @@ static ssize_t pqi_raid_bypass_cnt_show(struct device *dev,
struct scsi_device *sdev;
struct pqi_scsi_dev *device;
unsigned long flags;
int raid_bypass_cnt;
unsigned int raid_bypass_cnt;
sdev = to_scsi_device(dev);
ctrl_info = shost_to_hba(sdev->host);
@ -7304,7 +7304,7 @@ static ssize_t pqi_raid_bypass_cnt_show(struct device *dev,
return -ENODEV;
}
raid_bypass_cnt = atomic_read(&device->raid_bypass_cnt);
raid_bypass_cnt = device->raid_bypass_cnt;
spin_unlock_irqrestore(&ctrl_info->scsi_device_list_lock, flags);