6.1-stable review patch. If anyone has any objections, please let me know.
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From: Mike McGowen mike.mcgowen@microchip.com
[ Upstream commit 80d560d94fa9b28069c62e1a64ae4a03d5f43fbc ]
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 Stable-dep-of: b518e86d1a70 ("scsi: smartpqi: Fix device resources accessed after device removal") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/smartpqi/smartpqi.h | 2 +- drivers/scsi/smartpqi/smartpqi_init.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h index af27bb0f3133e..6e2f08ac68166 100644 --- a/drivers/scsi/smartpqi/smartpqi.h +++ b/drivers/scsi/smartpqi/smartpqi.h @@ -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 */ diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c index d97946a09f646..4822b830ea371 100644 --- a/drivers/scsi/smartpqi/smartpqi_init.c +++ b/drivers/scsi/smartpqi/smartpqi_init.c @@ -6035,7 +6035,7 @@ 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) @@ -7274,7 +7274,7 @@ 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); @@ -7290,7 +7290,7 @@ 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);