The request associated with a scsi command coming from the block layer
has a unique tag, so use that when possible for getting a CCB.
Unfortunately we don't support reserved commands in the SCSI midlayer yet,
so in the interim continue to manage those tags internally (along with
tags for private commands).
Signed-off-by: John Garry <john.garry@huawei.com>
---
drivers/scsi/pm8001/pm8001_init.c | 12 ++++--------
drivers/scsi/pm8001/pm8001_sas.c | 16 ++++++++++++----
drivers/scsi/pm8001/pm8001_sas.h | 11 ++++++++---
drivers/scsi/pm8001/pm80xx_hwi.c | 17 +++--------------
4 files changed, 27 insertions(+), 29 deletions(-)
diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index 0edc9857a8bd..abb884ddcaf9 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -196,7 +196,7 @@ static void pm8001_free(struct pm8001_hba_info *pm8001_ha)
}
PM8001_CHIP_DISP->chip_iounmap(pm8001_ha);
flush_workqueue(pm8001_wq);
- bitmap_free(pm8001_ha->tags);
+ bitmap_free(pm8001_ha->rsvd_tags);
kfree(pm8001_ha);
}
@@ -1208,18 +1208,15 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
struct Scsi_Host *shost = pm8001_ha->shost;
struct device *dev = pm8001_ha->dev;
u32 max_out_io, ccb_count;
- u32 can_queue;
int i;
max_out_io = pm8001_ha->main_cfg_tbl.pm80xx_tbl.max_out_io;
ccb_count = min_t(int, PM8001_MAX_CCB, max_out_io);
- /* Update to the scsi host*/
- can_queue = ccb_count - PM8001_RESERVE_SLOT;
- shost->can_queue = can_queue;
+ shost->can_queue = ccb_count - PM8001_RESERVE_SLOT;
- pm8001_ha->tags = bitmap_zalloc(ccb_count, GFP_KERNEL);
- if (!pm8001_ha->tags)
+ pm8001_ha->rsvd_tags = bitmap_zalloc(PM8001_RESERVE_SLOT, GFP_KERNEL);
+ if (!pm8001_ha->rsvd_tags)
goto err_out;
/* Memory region for ccb_info*/
@@ -1244,7 +1241,6 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
pm8001_ha->ccb_info[i].task = NULL;
pm8001_ha->ccb_info[i].ccb_tag = PM8001_INVALID_TAG;
pm8001_ha->ccb_info[i].device = NULL;
- ++pm8001_ha->tags_num;
}
return 0;
diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index 066dfa9f4683..d60bc311a4e9 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -65,9 +65,14 @@ static int pm8001_find_tag(struct sas_task *task, u32 *tag)
*/
void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
{
- void *bitmap = pm8001_ha->tags;
+ void *bitmap = pm8001_ha->rsvd_tags;
unsigned long flags;
+ if (tag < pm8001_ha->shost->can_queue)
+ return;
+
+ tag -= pm8001_ha->shost->can_queue;
+
spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
__clear_bit(tag, bitmap);
spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
@@ -80,18 +85,21 @@ void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
*/
int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
{
- void *bitmap = pm8001_ha->tags;
+ void *bitmap = pm8001_ha->rsvd_tags;
unsigned long flags;
unsigned int tag;
spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
- tag = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
- if (tag >= pm8001_ha->tags_num) {
+ tag = find_first_zero_bit(bitmap, PM8001_RESERVE_SLOT);
+ if (tag >= PM8001_RESERVE_SLOT) {
spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
return -SAS_QUEUE_FULL;
}
__set_bit(tag, bitmap);
spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
+
+ /* reserved tags are in the upper region of the tagset */
+ tag += pm8001_ha->shost->can_queue;
*tag_out = tag;
return 0;
}
diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h
index 9acaadf02150..ba32b009f412 100644
--- a/drivers/scsi/pm8001/pm8001_sas.h
+++ b/drivers/scsi/pm8001/pm8001_sas.h
@@ -510,8 +510,7 @@ struct pm8001_hba_info {
u32 chip_id;
const struct pm8001_chip_info *chip;
struct completion *nvmd_completion;
- int tags_num;
- unsigned long *tags;
+ unsigned long *rsvd_tags;
struct pm8001_phy phy[PM8001_MAX_PHYS];
struct pm8001_port port[PM8001_MAX_PHYS];
u32 id;
@@ -737,9 +736,15 @@ pm8001_ccb_alloc(struct pm8001_hba_info *pm8001_ha,
struct pm8001_device *dev, struct sas_task *task)
{
struct pm8001_ccb_info *ccb;
+ struct request *rq = NULL;
u32 tag;
- if (pm8001_tag_alloc(pm8001_ha, &tag)) {
+ if (task)
+ rq = sas_task_find_rq(task);
+
+ if (rq) {
+ tag = rq->tag;
+ } else if (pm8001_tag_alloc(pm8001_ha, &tag)) {
pm8001_dbg(pm8001_ha, FAIL, "Failed to allocate a tag\n");
return NULL;
}
diff --git a/drivers/scsi/pm8001/pm80xx_hwi.c b/drivers/scsi/pm8001/pm80xx_hwi.c
index 4484c498bcb6..ed2d65d3749a 100644
--- a/drivers/scsi/pm8001/pm80xx_hwi.c
+++ b/drivers/scsi/pm8001/pm80xx_hwi.c
@@ -4247,24 +4247,13 @@ static int check_enc_sat_cmd(struct sas_task *task)
static u32 pm80xx_chip_get_q_index(struct sas_task *task)
{
- struct scsi_cmnd *scmd = NULL;
+ struct request *rq = sas_task_find_rq(task);
u32 blk_tag;
- if (task->uldd_task) {
- struct ata_queued_cmd *qc;
-
- if (dev_is_sata(task->dev)) {
- qc = task->uldd_task;
- scmd = qc->scsicmd;
- } else {
- scmd = task->uldd_task;
- }
- }
-
- if (!scmd)
+ if (!rq)
return 0;
- blk_tag = blk_mq_unique_tag(scsi_cmd_to_rq(scmd));
+ blk_tag = blk_mq_unique_tag(rq);
return blk_mq_unique_tag_to_hwq(blk_tag);
}
--
2.35.3On 9/30/22 10:56, John Garry wrote:
> The request associated with a scsi command coming from the block layer
> has a unique tag, so use that when possible for getting a CCB.
>
> Unfortunately we don't support reserved commands in the SCSI midlayer yet,
> so in the interim continue to manage those tags internally (along with
> tags for private commands).
>
> Signed-off-by: John Garry <john.garry@huawei.com>
> ---
> drivers/scsi/pm8001/pm8001_init.c | 12 ++++--------
> drivers/scsi/pm8001/pm8001_sas.c | 16 ++++++++++++----
> drivers/scsi/pm8001/pm8001_sas.h | 11 ++++++++---
> drivers/scsi/pm8001/pm80xx_hwi.c | 17 +++--------------
> 4 files changed, 27 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
> index 0edc9857a8bd..abb884ddcaf9 100644
> --- a/drivers/scsi/pm8001/pm8001_init.c
> +++ b/drivers/scsi/pm8001/pm8001_init.c
> @@ -196,7 +196,7 @@ static void pm8001_free(struct pm8001_hba_info *pm8001_ha)
> }
> PM8001_CHIP_DISP->chip_iounmap(pm8001_ha);
> flush_workqueue(pm8001_wq);
> - bitmap_free(pm8001_ha->tags);
> + bitmap_free(pm8001_ha->rsvd_tags);
> kfree(pm8001_ha);
> }
>
> @@ -1208,18 +1208,15 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
> struct Scsi_Host *shost = pm8001_ha->shost;
> struct device *dev = pm8001_ha->dev;
> u32 max_out_io, ccb_count;
> - u32 can_queue;
> int i;
>
> max_out_io = pm8001_ha->main_cfg_tbl.pm80xx_tbl.max_out_io;
> ccb_count = min_t(int, PM8001_MAX_CCB, max_out_io);
>
> - /* Update to the scsi host*/
> - can_queue = ccb_count - PM8001_RESERVE_SLOT;
> - shost->can_queue = can_queue;
> + shost->can_queue = ccb_count - PM8001_RESERVE_SLOT;
>
> - pm8001_ha->tags = bitmap_zalloc(ccb_count, GFP_KERNEL);
> - if (!pm8001_ha->tags)
> + pm8001_ha->rsvd_tags = bitmap_zalloc(PM8001_RESERVE_SLOT, GFP_KERNEL);
> + if (!pm8001_ha->rsvd_tags)
> goto err_out;
>
> /* Memory region for ccb_info*/
> @@ -1244,7 +1241,6 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
> pm8001_ha->ccb_info[i].task = NULL;
> pm8001_ha->ccb_info[i].ccb_tag = PM8001_INVALID_TAG;
> pm8001_ha->ccb_info[i].device = NULL;
> - ++pm8001_ha->tags_num;
> }
>
> return 0;
> diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
> index 066dfa9f4683..d60bc311a4e9 100644
> --- a/drivers/scsi/pm8001/pm8001_sas.c
> +++ b/drivers/scsi/pm8001/pm8001_sas.c
> @@ -65,9 +65,14 @@ static int pm8001_find_tag(struct sas_task *task, u32 *tag)
> */
> void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
> {
> - void *bitmap = pm8001_ha->tags;
> + void *bitmap = pm8001_ha->rsvd_tags;
> unsigned long flags;
>
> + if (tag < pm8001_ha->shost->can_queue)
> + return;
> +
> + tag -= pm8001_ha->shost->can_queue;
> +
> spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
> __clear_bit(tag, bitmap);
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> @@ -80,18 +85,21 @@ void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
> */
> int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
> {
> - void *bitmap = pm8001_ha->tags;
> + void *bitmap = pm8001_ha->rsvd_tags;
> unsigned long flags;
> unsigned int tag;
>
> spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
> - tag = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
> - if (tag >= pm8001_ha->tags_num) {
> + tag = find_first_zero_bit(bitmap, PM8001_RESERVE_SLOT);
> + if (tag >= PM8001_RESERVE_SLOT) {
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> return -SAS_QUEUE_FULL;
> }
> __set_bit(tag, bitmap);
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> +
> + /* reserved tags are in the upper region of the tagset */
> + tag += pm8001_ha->shost->can_queue;
> *tag_out = tag;
> return 0;
> }
Can you move the reserved tags to the _lower_ region of the tagset?
That way the tag allocation scheme matches with what the block-layer
does, and the eventual conversion to reserved tags becomes easier.
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@suse.de +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman
On 04/10/2022 06:53, Hannes Reinecke wrote:
>> - void *bitmap = pm8001_ha->tags;
>> + void *bitmap = pm8001_ha->rsvd_tags;
>> unsigned long flags;
>> unsigned int tag;
>> spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
>> - tag = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
>> - if (tag >= pm8001_ha->tags_num) {
>> + tag = find_first_zero_bit(bitmap, PM8001_RESERVE_SLOT);
>> + if (tag >= PM8001_RESERVE_SLOT) {
>> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
>> return -SAS_QUEUE_FULL;
>> }
>> __set_bit(tag, bitmap);
>> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
>> +
>> + /* reserved tags are in the upper region of the tagset */
>> + tag += pm8001_ha->shost->can_queue;
>> *tag_out = tag;
>> return 0;
>> }
> Can you move the reserved tags to the _lower_ region of the tagset?
> That way the tag allocation scheme matches with what the block-layer
> does, and the eventual conversion to reserved tags becomes easier.
Yeah, I agree that having a scheme which matches the block layer would
be good for consistency and I will make that change, but I am not sure
how it helps conversion to reserved tags.
Thanks,
John
On Fri, Sep 30, 2022 at 11:03 AM John Garry <john.garry@huawei.com> wrote:
>
> The request associated with a scsi command coming from the block layer
> has a unique tag, so use that when possible for getting a CCB.
>
> Unfortunately we don't support reserved commands in the SCSI midlayer yet,
> so in the interim continue to manage those tags internally (along with
> tags for private commands).
>
> Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Jack Wang <jinpu.wang@ionos.com>
nice, I would expect this can improve performance, do you have numbers?
> ---
> drivers/scsi/pm8001/pm8001_init.c | 12 ++++--------
> drivers/scsi/pm8001/pm8001_sas.c | 16 ++++++++++++----
> drivers/scsi/pm8001/pm8001_sas.h | 11 ++++++++---
> drivers/scsi/pm8001/pm80xx_hwi.c | 17 +++--------------
> 4 files changed, 27 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
> index 0edc9857a8bd..abb884ddcaf9 100644
> --- a/drivers/scsi/pm8001/pm8001_init.c
> +++ b/drivers/scsi/pm8001/pm8001_init.c
> @@ -196,7 +196,7 @@ static void pm8001_free(struct pm8001_hba_info *pm8001_ha)
> }
> PM8001_CHIP_DISP->chip_iounmap(pm8001_ha);
> flush_workqueue(pm8001_wq);
> - bitmap_free(pm8001_ha->tags);
> + bitmap_free(pm8001_ha->rsvd_tags);
> kfree(pm8001_ha);
> }
>
> @@ -1208,18 +1208,15 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
> struct Scsi_Host *shost = pm8001_ha->shost;
> struct device *dev = pm8001_ha->dev;
> u32 max_out_io, ccb_count;
> - u32 can_queue;
> int i;
>
> max_out_io = pm8001_ha->main_cfg_tbl.pm80xx_tbl.max_out_io;
> ccb_count = min_t(int, PM8001_MAX_CCB, max_out_io);
>
> - /* Update to the scsi host*/
> - can_queue = ccb_count - PM8001_RESERVE_SLOT;
> - shost->can_queue = can_queue;
> + shost->can_queue = ccb_count - PM8001_RESERVE_SLOT;
>
> - pm8001_ha->tags = bitmap_zalloc(ccb_count, GFP_KERNEL);
> - if (!pm8001_ha->tags)
> + pm8001_ha->rsvd_tags = bitmap_zalloc(PM8001_RESERVE_SLOT, GFP_KERNEL);
> + if (!pm8001_ha->rsvd_tags)
> goto err_out;
>
> /* Memory region for ccb_info*/
> @@ -1244,7 +1241,6 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
> pm8001_ha->ccb_info[i].task = NULL;
> pm8001_ha->ccb_info[i].ccb_tag = PM8001_INVALID_TAG;
> pm8001_ha->ccb_info[i].device = NULL;
> - ++pm8001_ha->tags_num;
> }
>
> return 0;
> diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
> index 066dfa9f4683..d60bc311a4e9 100644
> --- a/drivers/scsi/pm8001/pm8001_sas.c
> +++ b/drivers/scsi/pm8001/pm8001_sas.c
> @@ -65,9 +65,14 @@ static int pm8001_find_tag(struct sas_task *task, u32 *tag)
> */
> void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
> {
> - void *bitmap = pm8001_ha->tags;
> + void *bitmap = pm8001_ha->rsvd_tags;
> unsigned long flags;
>
> + if (tag < pm8001_ha->shost->can_queue)
> + return;
> +
> + tag -= pm8001_ha->shost->can_queue;
> +
> spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
> __clear_bit(tag, bitmap);
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> @@ -80,18 +85,21 @@ void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
> */
> int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
> {
> - void *bitmap = pm8001_ha->tags;
> + void *bitmap = pm8001_ha->rsvd_tags;
> unsigned long flags;
> unsigned int tag;
>
> spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
> - tag = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
> - if (tag >= pm8001_ha->tags_num) {
> + tag = find_first_zero_bit(bitmap, PM8001_RESERVE_SLOT);
> + if (tag >= PM8001_RESERVE_SLOT) {
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> return -SAS_QUEUE_FULL;
> }
> __set_bit(tag, bitmap);
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> +
> + /* reserved tags are in the upper region of the tagset */
> + tag += pm8001_ha->shost->can_queue;
> *tag_out = tag;
> return 0;
> }
> diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h
> index 9acaadf02150..ba32b009f412 100644
> --- a/drivers/scsi/pm8001/pm8001_sas.h
> +++ b/drivers/scsi/pm8001/pm8001_sas.h
> @@ -510,8 +510,7 @@ struct pm8001_hba_info {
> u32 chip_id;
> const struct pm8001_chip_info *chip;
> struct completion *nvmd_completion;
> - int tags_num;
> - unsigned long *tags;
> + unsigned long *rsvd_tags;
> struct pm8001_phy phy[PM8001_MAX_PHYS];
> struct pm8001_port port[PM8001_MAX_PHYS];
> u32 id;
> @@ -737,9 +736,15 @@ pm8001_ccb_alloc(struct pm8001_hba_info *pm8001_ha,
> struct pm8001_device *dev, struct sas_task *task)
> {
> struct pm8001_ccb_info *ccb;
> + struct request *rq = NULL;
> u32 tag;
>
> - if (pm8001_tag_alloc(pm8001_ha, &tag)) {
> + if (task)
> + rq = sas_task_find_rq(task);
> +
> + if (rq) {
> + tag = rq->tag;
> + } else if (pm8001_tag_alloc(pm8001_ha, &tag)) {
> pm8001_dbg(pm8001_ha, FAIL, "Failed to allocate a tag\n");
> return NULL;
> }
> diff --git a/drivers/scsi/pm8001/pm80xx_hwi.c b/drivers/scsi/pm8001/pm80xx_hwi.c
> index 4484c498bcb6..ed2d65d3749a 100644
> --- a/drivers/scsi/pm8001/pm80xx_hwi.c
> +++ b/drivers/scsi/pm8001/pm80xx_hwi.c
> @@ -4247,24 +4247,13 @@ static int check_enc_sat_cmd(struct sas_task *task)
>
> static u32 pm80xx_chip_get_q_index(struct sas_task *task)
> {
> - struct scsi_cmnd *scmd = NULL;
> + struct request *rq = sas_task_find_rq(task);
> u32 blk_tag;
>
> - if (task->uldd_task) {
> - struct ata_queued_cmd *qc;
> -
> - if (dev_is_sata(task->dev)) {
> - qc = task->uldd_task;
> - scmd = qc->scsicmd;
> - } else {
> - scmd = task->uldd_task;
> - }
> - }
> -
> - if (!scmd)
> + if (!rq)
> return 0;
>
> - blk_tag = blk_mq_unique_tag(scsi_cmd_to_rq(scmd));
> + blk_tag = blk_mq_unique_tag(rq);
> return blk_mq_unique_tag_to_hwq(blk_tag);
> }
>
> --
> 2.35.3
>
On 30/09/2022 10:17, Jinpu Wang wrote:
> On Fri, Sep 30, 2022 at 11:03 AM John Garry<john.garry@huawei.com> wrote:
>> The request associated with a scsi command coming from the block layer
>> has a unique tag, so use that when possible for getting a CCB.
>>
>> Unfortunately we don't support reserved commands in the SCSI midlayer yet,
>> so in the interim continue to manage those tags internally (along with
>> tags for private commands).
>>
>> Signed-off-by: John Garry<john.garry@huawei.com>
> Reviewed-by: Jack Wang<jinpu.wang@ionos.com>
> nice, I would expect this can improve performance, do you have numbers?
Unfortunately my system hangs after I run for an appreciable period of
time. I normally get around it by turning on much heavy debug options,
but that would not be much use for performance testing.
But we did get considerable performance improvement for hisi_sas when we
made the equivalent change.
Damien, if you are interested then sharing any results would be great.
BTW, I do notice that we still have this global lock in delivery path
which should be removed at some stage:
int mvs_queue_command(struct sas_task *task, gfp_t gfp_flags)
{
...
spin_lock_irqsave(&mvi->lock, flags);
rc = mvs_task_prep(task, mvi, is_tmf, tmf, &pass);
...
spin_unlock_irqrestore(&mvi->lock, flags);
}
That really will affect performance...
Thanks,
John
On 30/09/2022 11:20, John Garry wrote:
> BTW, I do notice that we still have this global lock in delivery path
> which should be removed at some stage:
> > int mvs_queue_command(struct sas_task *task, gfp_t gfp_flags)
> {
> ...
>
> spin_lock_irqsave(&mvi->lock, flags);
> rc = mvs_task_prep(task, mvi, is_tmf, tmf, &pass);
> ...
> spin_unlock_irqrestore(&mvi->lock, flags);
> }
>
oops... that's mvsas. But pm8001 does still use a big lock (which we
should get rid off):
int pm8001_queue_command(struct sas_task *task, gfp_t gfp_flags)
{
...
pm8001_dbg(pm8001_ha, IO, "pm8001_task_exec device\n");
spin_lock_irqsave(&pm8001_ha->lock, flags);
Thanks,
John
> That really will affect performance...
On Fri, Sep 30, 2022 at 1:05 PM John Garry <john.garry@huawei.com> wrote:
>
> On 30/09/2022 11:20, John Garry wrote:
> > BTW, I do notice that we still have this global lock in delivery path
> > which should be removed at some stage:
> > > int mvs_queue_command(struct sas_task *task, gfp_t gfp_flags)
> > {
> > ...
> >
> > spin_lock_irqsave(&mvi->lock, flags);
> > rc = mvs_task_prep(task, mvi, is_tmf, tmf, &pass);
> > ...
> > spin_unlock_irqrestore(&mvi->lock, flags);
> > }
> >
>
> oops... that's mvsas. But pm8001 does still use a big lock (which we
> should get rid off):
Yes, would be great to get rid of the per ha lock.
>
> int pm8001_queue_command(struct sas_task *task, gfp_t gfp_flags)
> {
> ...
> pm8001_dbg(pm8001_ha, IO, "pm8001_task_exec device\n");
>
> spin_lock_irqsave(&pm8001_ha->lock, flags);
>
>
> Thanks,
> John
>
> > That really will affect performance...
>
© 2016 - 2026 Red Hat, Inc.