leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

scsi: smartpqi: Add stream detection

Browse Source 
Enhance performance by adding sequential stream detection for RAID5/RAID6
sequential write requests. Reduce stripe lock contention with full-stripe
write operations.

There is one common stripe lock for each RAID volume that can be set by
either the RAID engine or the AIO engine. The AIO path has I/O request
sizes well below the stripe size resulting in many Read-Modify-Write
operations.

Sending the request to the RAID engine allows for coalescing requests into
full stripe operations resulting in reduced Read-Modify-Write operations.

Link: https://lore.kernel.org/r/161549375693.25025.2962141451773219796.stgit@brunhilda
Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Mike McGowen <mike.mcgowen@microchip.com>
Reviewed-by: Scott Teel <scott.teel@microchip.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Don Brace 2021-03-11 14:15:56 -06:00 committed by Martin K. Petersen
parent 583891c9e5
commit c7ffedb3a7
2 changed files with 90 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
drivers/scsi/smartpqi/smartpqi.h
View File

@ -1043,6 +1043,13 @@ struct pqi_scsi_dev_raid_map_data {
#define RAID_CTLR_LUNID "\0\0\0\0\0\0\0\0"
#define NUM_STREAMS_PER_LUN 8
struct pqi_stream_data {
u64 next_lba;
u32 last_accessed;
};
struct pqi_scsi_dev {
int devtype; /* as reported by INQUIRY commmand */
u8 device_type; /* as reported by */
@ -1097,6 +1104,7 @@ struct pqi_scsi_dev {
struct list_head add_list_entry;
struct list_head delete_list_entry;
struct pqi_stream_data stream_data[NUM_STREAMS_PER_LUN];
atomic_t scsi_cmds_outstanding;
atomic_t raid_bypass_cnt;
};
@ -1296,6 +1304,7 @@ struct pqi_ctrl_info {
u8 enable_r5_writes : 1;
u8 enable_r6_writes : 1;
u8 lv_drive_type_mix_valid : 1;
u8 enable_stream_detection : 1;
u8 ciss_report_log_flags;
u32 max_transfer_encrypted_sas_sata;

87
drivers/scsi/smartpqi/smartpqi_init.c
View File

@ -5688,8 +5688,82 @@ void pqi_prep_for_scsi_done(struct scsi_cmnd *scmd)
atomic_dec(&device->scsi_cmds_outstanding);
}
static int pqi_scsi_queue_command(struct Scsi_Host *shost,
static bool pqi_is_parity_write_stream(struct pqi_ctrl_info *ctrl_info,
struct scsi_cmnd *scmd)
{
u32 oldest_jiffies;
u8 lru_index;
int i;
int rc;
struct pqi_scsi_dev *device;
struct pqi_stream_data *pqi_stream_data;
struct pqi_scsi_dev_raid_map_data rmd;
if (!ctrl_info->enable_stream_detection)
return false;
rc = pqi_get_aio_lba_and_block_count(scmd, &rmd);
if (rc)
return false;
/* Check writes only. */
if (!rmd.is_write)
return false;
device = scmd->device->hostdata;
/* Check for RAID 5/6 streams. */
if (device->raid_level != SA_RAID_5 && device->raid_level != SA_RAID_6)
return false;
/*
* If controller does not support AIO RAID{5,6} writes, need to send
* requests down non-AIO path.
*/
if ((device->raid_level == SA_RAID_5 && !ctrl_info->enable_r5_writes) ||
(device->raid_level == SA_RAID_6 && !ctrl_info->enable_r6_writes))
return true;
lru_index = 0;
oldest_jiffies = INT_MAX;
for (i = 0; i < NUM_STREAMS_PER_LUN; i++) {
pqi_stream_data = &device->stream_data[i];
/*
* Check for adjacent request or request is within
* the previous request.
*/
if ((pqi_stream_data->next_lba &&
rmd.first_block >= pqi_stream_data->next_lba) &&
rmd.first_block <= pqi_stream_data->next_lba +
rmd.block_cnt) {
pqi_stream_data->next_lba = rmd.first_block +
rmd.block_cnt;
pqi_stream_data->last_accessed = jiffies;
return true;
}
/* unused entry */
if (pqi_stream_data->last_accessed == 0) {
lru_index = i;
break;
}
/* Find entry with oldest last accessed time. */
if (pqi_stream_data->last_accessed <= oldest_jiffies) {
oldest_jiffies = pqi_stream_data->last_accessed;
lru_index = i;
}
}
/* Set LRU entry. */
pqi_stream_data = &device->stream_data[lru_index];
pqi_stream_data->last_accessed = jiffies;
pqi_stream_data->next_lba = rmd.first_block + rmd.block_cnt;
return false;
}
static int pqi_scsi_queue_command(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
{
int rc;
struct pqi_ctrl_info *ctrl_info;
@ -5736,11 +5810,12 @@ static int pqi_scsi_queue_command(struct Scsi_Host *shost,
raid_bypassed = false;
if (device->raid_bypass_enabled &&
!blk_rq_is_passthrough(scmd->request)) {
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);
if (!pqi_is_parity_write_stream(ctrl_info, scmd)) {
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);
}
}
}
if (!raid_bypassed)