[PATCH v2] mpt3sas: Added support for shared host tagset for cpuhotplug

[PATCH v2] mpt3sas: Added support for shared host tagset for cpuhotplug

[Sreekanth Reddy]

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MPT Fusion adapters can steer completions to individual queues, and
we now have support for shared host-wide tags.
So we can enable multiqueue support for MPT fusion adapters.

Once driver enable shared host-wide tags, cpu hotplug feature is also
supported as it was enabled using below patchsets -
commit bf0beec060 ("blk-mq: drain I/O when all CPUs in a hctx are
offline")

Currently the driver has provision to disable host-wide tags using
"host_tagset_enable" module parameter.

Once we do not have any major performance regression using host-wide
tags, we will drop the hand-crafted interrupt affinity settings.

Performance is also meeting the expectation - (used both none and
mq-deadline scheduler)
24 Drive SSD on Aero with/without this patch can get 3.1M IOPs"

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
---

v2:
   Fix the error reported by kernel test robot

 drivers/scsi/mpt3sas/mpt3sas_base.c  | 50 ++++++++++++++++++----------
 drivers/scsi/mpt3sas/mpt3sas_base.h  |  1 +
 drivers/scsi/mpt3sas/mpt3sas_scsih.c | 42 ++++++++++++++++++++++-
 3 files changed, 75 insertions(+), 18 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index f5582c8..84663d1 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -3648,25 +3648,16 @@ _base_get_msix_index(struct MPT3SAS_ADAPTER *ioc,
 		    base_mod64(atomic64_add_return(1,
 		    &ioc->total_io_cnt), ioc->reply_queue_count) : 0;
 
-	return ioc->cpu_msix_table[raw_smp_processor_id()];
-}
+	if (scmd && ioc->shost->nr_hw_queues > 1) {
+		u32 tag = blk_mq_unique_tag(scmd->request);
 
-/**
- * _base_sdev_nr_inflight_request -get number of inflight requests
- *				   of a request queue.
- * @q: request_queue object
- *
- * returns number of inflight request of a request queue.
- */
-inline unsigned long
-_base_sdev_nr_inflight_request(struct request_queue *q)
-{
-	struct blk_mq_hw_ctx *hctx = q->queue_hw_ctx[0];
+		return blk_mq_unique_tag_to_hwq(tag) +
+			ioc->high_iops_queues;
+	}
 
-	return atomic_read(&hctx->nr_active);
+	return ioc->cpu_msix_table[raw_smp_processor_id()];
 }
 
-
 /**
  * _base_get_high_iops_msix_index - get the msix index of
  *				high iops queues
@@ -3686,7 +3677,8 @@ _base_get_high_iops_msix_index(struct MPT3SAS_ADAPTER *ioc,
 	 * reply queues in terms of batch count 16 when outstanding
 	 * IOs on the target device is >=8.
 	 */
-	if (_base_sdev_nr_inflight_request(scmd->device->request_queue) >
+
+	if (atomic_read(&scmd->device->device_busy) >
 	    MPT3SAS_DEVICE_HIGH_IOPS_DEPTH)
 		return base_mod64((
 		    atomic64_add_return(1, &ioc->high_iops_outstanding) /
@@ -3739,8 +3731,23 @@ mpt3sas_base_get_smid_scsiio(struct MPT3SAS_ADAPTER *ioc, u8 cb_idx,
 	struct scsi_cmnd *scmd)
 {
 	struct scsiio_tracker *request = scsi_cmd_priv(scmd);
-	unsigned int tag = scmd->request->tag;
 	u16 smid;
+	u32 tag, unique_tag;
+
+	unique_tag = blk_mq_unique_tag(scmd->request);
+	tag = blk_mq_unique_tag_to_tag(unique_tag);
+
+	/*
+	 * store hw queue number corresponding to the tag,
+	 * this hw queue number is used later to determine
+	 * the unqiue_tag using below logic. This unique_tag
+	 * is used to retrieve the scmd pointer corresponding
+	 * to tag using scsi_host_find_tag() API,
+	 *
+	 * tag = smid - 1;
+	 * unique_tag = ioc->io_queue_num[tag] << BLK_MQ_UNIQUE_TAG_BITS | tag;
+	 */
+	ioc->io_queue_num[tag] = blk_mq_unique_tag_to_hwq(unique_tag);
 
 	smid = tag + 1;
 	request->cb_idx = cb_idx;
@@ -3831,6 +3838,7 @@ mpt3sas_base_free_smid(struct MPT3SAS_ADAPTER *ioc, u16 smid)
 
 		mpt3sas_base_clear_st(ioc, st);
 		_base_recovery_check(ioc);
+		ioc->io_queue_num[smid - 1] = 0;
 		return;
 	}
 
@@ -5362,6 +5370,9 @@ _base_release_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 		kfree(ioc->chain_lookup);
 		ioc->chain_lookup = NULL;
 	}
+
+	kfree(ioc->io_queue_num);
+	ioc->io_queue_num = NULL;
 }
 
 /**
@@ -5772,6 +5783,11 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 		    ioc_info(ioc, "internal(0x%p): depth(%d), start smid(%d)\n",
 			     ioc->internal,
 			     ioc->internal_depth, ioc->internal_smid));
+
+	ioc->io_queue_num = kcalloc(ioc->scsiio_depth,
+	    sizeof(u16), GFP_KERNEL);
+	if (!ioc->io_queue_num)
+		goto out;
 	/*
 	 * The number of NVMe page sized blocks needed is:
 	 *     (((sg_tablesize * 8) - 1) / (page_size - 8)) + 1
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
index 2def7a3..2eb94e4 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
@@ -1439,6 +1439,7 @@ struct MPT3SAS_ADAPTER {
 	spinlock_t	scsi_lookup_lock;
 	int		pending_io_count;
 	wait_queue_head_t reset_wq;
+	u16		*io_queue_num;
 
 	/* PCIe SGL */
 	struct dma_pool *pcie_sgl_dma_pool;
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index c8b09a8..6973041 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -54,6 +54,7 @@
 #include <linux/interrupt.h>
 #include <linux/aer.h>
 #include <linux/raid_class.h>
+#include <linux/blk-mq-pci.h>
 #include <asm/unaligned.h>
 
 #include "mpt3sas_base.h"
@@ -168,6 +169,11 @@ MODULE_PARM_DESC(multipath_on_hba,
 	"\t SAS 2.0 & SAS 3.0 HBA - This will be disabled,\n\t\t"
 	"\t SAS 3.5 HBA - This will be enabled)");
 
+static int host_tagset_enable = 1;
+module_param(host_tagset_enable, int, 0444);
+MODULE_PARM_DESC(host_tagset_enable,
+	"Shared host tagset enable/disable Default: enable(1)");
+
 /* raid transport support */
 static struct raid_template *mpt3sas_raid_template;
 static struct raid_template *mpt2sas_raid_template;
@@ -1743,10 +1749,12 @@ mpt3sas_scsih_scsi_lookup_get(struct MPT3SAS_ADAPTER *ioc, u16 smid)
 	struct scsi_cmnd *scmd = NULL;
 	struct scsiio_tracker *st;
 	Mpi25SCSIIORequest_t *mpi_request;
+	u16 tag = smid - 1;
 
 	if (smid > 0  &&
 	    smid <= ioc->scsiio_depth - INTERNAL_SCSIIO_CMDS_COUNT) {
-		u32 unique_tag = smid - 1;
+		u32 unique_tag =
+		    ioc->io_queue_num[tag] << BLK_MQ_UNIQUE_TAG_BITS | tag;
 
 		mpi_request = mpt3sas_base_get_msg_frame(ioc, smid);
 
@@ -11599,6 +11607,22 @@ scsih_scan_finished(struct Scsi_Host *shost, unsigned long time)
 	return 1;
 }
 
+/**
+ * scsih_map_queues - map reply queues with request queues
+ * @shost: SCSI host pointer
+ */
+static int scsih_map_queues(struct Scsi_Host *shost)
+{
+	struct MPT3SAS_ADAPTER *ioc =
+	    (struct MPT3SAS_ADAPTER *)shost->hostdata;
+
+	if (ioc->shost->nr_hw_queues == 1)
+		return 0;
+
+	return blk_mq_pci_map_queues(&shost->tag_set.map[HCTX_TYPE_DEFAULT],
+	    ioc->pdev, ioc->high_iops_queues);
+}
+
 /* shost template for SAS 2.0 HBA devices */
 static struct scsi_host_template mpt2sas_driver_template = {
 	.module				= THIS_MODULE,
@@ -11666,6 +11690,7 @@ static struct scsi_host_template mpt3sas_driver_template = {
 	.sdev_attrs			= mpt3sas_dev_attrs,
 	.track_queue_depth		= 1,
 	.cmd_size			= sizeof(struct scsiio_tracker),
+	.map_queues			= scsih_map_queues,
 };
 
 /* raid transport support for SAS 3.0 HBA devices */
@@ -12028,6 +12053,21 @@ _scsih_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	} else
 		ioc->hide_drives = 0;
 
+	shost->host_tagset = 0;
+	shost->nr_hw_queues = 1;
+
+	if (ioc->is_gen35_ioc && ioc->reply_queue_count > 1 &&
+	    host_tagset_enable && ioc->smp_affinity_enable) {
+
+		shost->host_tagset = 1;
+		shost->nr_hw_queues =
+		    ioc->reply_queue_count - ioc->high_iops_queues;
+
+		dev_info(&ioc->pdev->dev,
+		    "Max SCSIIO MPT commands: %d shared with nr_hw_queues = %d\n",
+		    shost->can_queue, shost->nr_hw_queues);
+	}
+
 	rv = scsi_add_host(shost, &pdev->dev);
 	if (rv) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
-- 
2.27.0


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Re: [PATCH v2] mpt3sas: Added support for shared host tagset for cpuhotplug

[Martin K. Petersen]

Sreekanth,

> MPT Fusion adapters can steer completions to individual queues, and we
> now have support for shared host-wide tags.  So we can enable
> multiqueue support for MPT fusion adapters.

Applied to 5.12/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH v2] mpt3sas: Added support for shared host tagset for cpuhotplug

[John Garry]

On 02/02/2021 09:58, Sreekanth Reddy wrote:
> d transport support for SAS 3.0 HBA devices */
> @@ -12028,6 +12053,21 @@ _scsih_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>   	} else
>   		ioc->hide_drives = 0;
>   
> +	shost->host_tagset = 0;
> +	shost->nr_hw_queues = 1;
> +
> +	if (ioc->is_gen35_ioc && ioc->reply_queue_count > 1 &&
> +	    host_tagset_enable && ioc->smp_affinity_enable) {
> +

I wanted to test host_tagset_enable feature on my LSI 3008 card (I think 
that it uses MP25 version), but is_gen35_ioc is not set there - is there 
some specific reason for which we can't support on that HW rev?

> +		shost->host_tagset = 1;
> +		shost->nr_hw_queues =
> +		    ioc->reply_queue_count - ioc->high_iops_queues;
> +
> +		dev_info(&ioc->pdev->dev,
> +		    "Max SCSIIO MPT commands: %d shared with nr_hw_queues = %d\n",
> +		    shost->can_queue, shost->nr_hw_queues);
> +	}

Thanks,
John

Re: [PATCH v2] mpt3sas: Added support for shared host tagset for cpuhotplug

[Suganath Prabu Subramani]

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On Tue, Apr 20, 2021 at 8:09 PM John Garry <john.garry@huawei.com> wrote:
>
> On 02/02/2021 09:58, Sreekanth Reddy wrote:
> > d transport support for SAS 3.0 HBA devices */
> > @@ -12028,6 +12053,21 @@ _scsih_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> >       } else
> >               ioc->hide_drives = 0;
> >
> > +     shost->host_tagset = 0;
> > +     shost->nr_hw_queues = 1;
> > +
> > +     if (ioc->is_gen35_ioc && ioc->reply_queue_count > 1 &&
> > +         host_tagset_enable && ioc->smp_affinity_enable) {
> > +
>
> I wanted to test host_tagset_enable feature on my LSI 3008 card (I think
> that it uses MP25 version), but is_gen35_ioc is not set there - is there
> some specific reason for which we can't support on that HW rev?
>
John,
We want to avoid any code changes for older generation controllers as much as
possible. Shared host tag is a major IO path change and for older generation
controllers it is better not to enable such feature and support.
"Fix engine policy for older controller"

> > +             shost->host_tagset = 1;
> > +             shost->nr_hw_queues =
> > +                 ioc->reply_queue_count - ioc->high_iops_queues;
> > +
> > +             dev_info(&ioc->pdev->dev,
> > +                 "Max SCSIIO MPT commands: %d shared with nr_hw_queues = %d\n",
> > +                 shost->can_queue, shost->nr_hw_queues);
> > +     }
>
> Thanks,
> John

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Re: [PATCH v2] mpt3sas: Added support for shared host tagset for cpuhotplug

[John Garry]

On 21/04/2021 11:20, Suganath Prabu Subramani wrote:
> On Tue, Apr 20, 2021 at 8:09 PM John Garry <john.garry@huawei.com> wrote:
>>
>> On 02/02/2021 09:58, Sreekanth Reddy wrote:
>>> d transport support for SAS 3.0 HBA devices */
>>> @@ -12028,6 +12053,21 @@ _scsih_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>>>        } else
>>>                ioc->hide_drives = 0;
>>>
>>> +     shost->host_tagset = 0;
>>> +     shost->nr_hw_queues = 1;
>>> +
>>> +     if (ioc->is_gen35_ioc && ioc->reply_queue_count > 1 &&

*

>>> +         host_tagset_enable && ioc->smp_affinity_enable) {
>>> +
>>
>> I wanted to test host_tagset_enable feature on my LSI 3008 card (I think
>> that it uses MP25 version), but is_gen35_ioc is not set there - is there
>> some specific reason for which we can't support on that HW rev?
>>
> John,
> We want to avoid any code changes for older generation controllers as much as
> possible. Shared host tag is a major IO path change and for older generation
> controllers it is better not to enable such feature and support.
> "Fix engine policy for older controller"

ok, understood.

But is there a change which you can share for me to test locally?

In the test for enabling, above *, I just locally removed the 
ioc->is_gen35_ioc condition and it looks to work ok. Is this good 
enough, or am I possibly doing something dangerous? I'd appreciate if 
you can share something for me to try locally.

Thanks,
John

> 
>>> +             shost->host_tagset = 1;
>>> +             shost->nr_hw_queues =
>>> +                 ioc->reply_queue_count - ioc->high_iops_queues;
>>> +
>>> +             dev_info(&ioc->pdev->dev,
>>> +                 "Max SCSIIO MPT commands: %d shared with nr_hw_queues = %d\n",
>>> +                 shost->can_queue, shost->nr_hw_queues);
>>> +     }
>>
>> Thanks,
>> John

Re: [PATCH v2] mpt3sas: Added support for shared host tagset for cpuhotplug

[Suganath Prabu Subramani]

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Hi John,

Removing ioc->is_gen35_ioc condition will enable Shared host tag.
We have not tested it with older generation of controllers.
I will test it and let you know.

Thanks,
Suganath


On Wed, Apr 21, 2021 at 3:57 PM John Garry <john.garry@huawei.com> wrote:
>
> On 21/04/2021 11:20, Suganath Prabu Subramani wrote:
> > On Tue, Apr 20, 2021 at 8:09 PM John Garry <john.garry@huawei.com> wrote:
> >>
> >> On 02/02/2021 09:58, Sreekanth Reddy wrote:
> >>> d transport support for SAS 3.0 HBA devices */
> >>> @@ -12028,6 +12053,21 @@ _scsih_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> >>>        } else
> >>>                ioc->hide_drives = 0;
> >>>
> >>> +     shost->host_tagset = 0;
> >>> +     shost->nr_hw_queues = 1;
> >>> +
> >>> +     if (ioc->is_gen35_ioc && ioc->reply_queue_count > 1 &&
>
> *
>
> >>> +         host_tagset_enable && ioc->smp_affinity_enable) {
> >>> +
> >>
> >> I wanted to test host_tagset_enable feature on my LSI 3008 card (I think
> >> that it uses MP25 version), but is_gen35_ioc is not set there - is there
> >> some specific reason for which we can't support on that HW rev?
> >>
> > John,
> > We want to avoid any code changes for older generation controllers as much as
> > possible. Shared host tag is a major IO path change and for older generation
> > controllers it is better not to enable such feature and support.
> > "Fix engine policy for older controller"
>
> ok, understood.
>
> But is there a change which you can share for me to test locally?
>
> In the test for enabling, above *, I just locally removed the
> ioc->is_gen35_ioc condition and it looks to work ok. Is this good
> enough, or am I possibly doing something dangerous? I'd appreciate if
> you can share something for me to try locally.
>
> Thanks,
> John
>
> >
> >>> +             shost->host_tagset = 1;
> >>> +             shost->nr_hw_queues =
> >>> +                 ioc->reply_queue_count - ioc->high_iops_queues;
> >>> +
> >>> +             dev_info(&ioc->pdev->dev,
> >>> +                 "Max SCSIIO MPT commands: %d shared with nr_hw_queues = %d\n",
> >>> +                 shost->can_queue, shost->nr_hw_queues);
> >>> +     }
> >>
> >> Thanks,
> >> John
>

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