| Message ID | 1571926881-75524-7-git-send-email-john.garry@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | hisi_sas: Expose multiple hw queues for v3 hw as experimental | expand |
On Thu, Oct 24, 2019 at 10:21:21PM +0800, John Garry wrote: > Since we're not ready to expose mutliple queues to the upper layer always > due to CPU hotplug issue, add a new interim experimental command line > option to support it. > > We still need to keep supporting auto_affine_msi_experimental, since > people are now replying the performance it provides, even though it is > unsafe. > > If auto_affine_msi_experimental and expose_mq_experimental are both set, > then auto_affine_msi_experimental takes preference. > > Signed-off-by: John Garry <john.garry@huawei.com> > --- > drivers/scsi/hisi_sas/hisi_sas.h | 2 + > drivers/scsi/hisi_sas/hisi_sas_main.c | 55 ++++++++++++++++---------- > drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 51 +++++++++++++++++++++--- > 3 files changed, 83 insertions(+), 25 deletions(-) > > diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h > index 4eb8f1c53f78..884f2426d753 100644 > --- a/drivers/scsi/hisi_sas/hisi_sas.h > +++ b/drivers/scsi/hisi_sas/hisi_sas.h > @@ -8,6 +8,8 @@ > #define _HISI_SAS_H_ > > #include <linux/acpi.h> > +#include <linux/blk-mq.h> > +#include <linux/blk-mq-pci.h> > #include <linux/clk.h> > #include <linux/debugfs.h> > #include <linux/dmapool.h> > diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c > index 53802c1cc1d0..c8c96a46acfd 100644 > --- a/drivers/scsi/hisi_sas/hisi_sas_main.c > +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c > @@ -389,9 +389,11 @@ static int hisi_sas_task_prep(struct sas_task *task, > struct hisi_sas_slot *slot; > struct hisi_sas_cmd_hdr *cmd_hdr_base; > struct asd_sas_port *sas_port = device->port; > + struct Scsi_Host *shost = hisi_hba->shost; > struct device *dev = hisi_hba->dev; > int dlvry_queue_slot, dlvry_queue, rc, slot_idx; > int n_elem = 0, n_elem_dif = 0, n_elem_req = 0; > + struct scsi_cmnd *scmd = NULL; > struct hisi_sas_dq *dq; > unsigned long flags; > int wr_q_index; > @@ -407,13 +409,38 @@ static int hisi_sas_task_prep(struct sas_task *task, > return -ECOMM; > } > > - if (hisi_hba->reply_map) { > - int cpu = raw_smp_processor_id(); > - unsigned int dq_index = hisi_hba->reply_map[cpu]; > + if (task->uldd_task) { > + struct ata_queued_cmd *qc; > > - *dq_pointer = dq = &hisi_hba->dq[dq_index]; > - } else { > + if (dev_is_sata(device)) { > + qc = task->uldd_task; > + scmd = qc->scsicmd; > + } else { > + scmd = task->uldd_task; > + } > + } > + > + /* We have to move to just a single mode: expose multiple queues */ > + if (!hisi_hba->reply_map && !shost->nr_hw_queues) { > *dq_pointer = dq = sas_dev->dq; > + } else { > + if (hisi_hba->reply_map) { > + int cpu = raw_smp_processor_id(); > + unsigned int dq_index = hisi_hba->reply_map[cpu]; > + > + *dq_pointer = dq = &hisi_hba->dq[dq_index]; > + } else { > + if (scmd) { > + unsigned int dq_index; > + u32 blk_tag; > + > + blk_tag = blk_mq_unique_tag(scmd->request); > + dq_index = blk_mq_unique_tag_to_hwq(blk_tag); > + *dq_pointer = dq = &hisi_hba->dq[dq_index]; > + } else { > + *dq_pointer = dq = sas_dev->dq; > + } > + } > } > > port = to_hisi_sas_port(sas_port); > @@ -438,22 +465,10 @@ static int hisi_sas_task_prep(struct sas_task *task, > } > > if (hisi_hba->hw->slot_index_alloc) > - rc = hisi_hba->hw->slot_index_alloc(hisi_hba, device, NULL); > - else { > - struct scsi_cmnd *scsi_cmnd = NULL; > - > - if (task->uldd_task) { > - struct ata_queued_cmd *qc; > + rc = hisi_hba->hw->slot_index_alloc(hisi_hba, device, scmd); > + else > + rc = hisi_sas_slot_index_alloc(hisi_hba, scmd); > > - if (dev_is_sata(device)) { > - qc = task->uldd_task; > - scsi_cmnd = qc->scsicmd; > - } else { > - scsi_cmnd = task->uldd_task; > - } > - } > - rc = hisi_sas_slot_index_alloc(hisi_hba, scsi_cmnd); > - } > if (rc < 0) > goto err_out_dif_dma_unmap; > > diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c > index 29119d0b27a7..03ba0416f910 100644 > --- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c > +++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c > @@ -512,6 +512,11 @@ module_param(auto_affine_msi_experimental, bool, 0444); > MODULE_PARM_DESC(auto_affine_msi_experimental, "Enable auto-affinity of MSI IRQs as experimental:\n" > "default is off"); > > +static bool expose_mq_experimental; > +module_param(expose_mq_experimental, bool, 0444); > +MODULE_PARM_DESC(expose_mq_experimental, "Expose multiple hw queues to upper layer as experimental:\n" > + "default is off"); > + > static u32 hisi_sas_read32(struct hisi_hba *hisi_hba, u32 off) > { > void __iomem *regs = hisi_hba->regs + off; > @@ -558,6 +563,11 @@ static u32 hisi_sas_phy_read32(struct hisi_hba *hisi_hba, > > static int bitmaps_alloc_v3_hw(struct hisi_hba *hisi_hba) > { > + if (expose_mq_experimental) > + return sbitmap_init_node(&hisi_hba->slot_index_tags, > + HISI_SAS_MAX_COMMANDS, -1, > + GFP_KERNEL, > + dev_to_node(hisi_hba->dev)); > return sbitmap_init_node(&hisi_hba->slot_index_tags, > HISI_SAS_UNRESERVED_IPTT, -1, > GFP_KERNEL, dev_to_node(hisi_hba->dev)); > @@ -570,6 +580,10 @@ static int slot_index_alloc_v3_hw(struct hisi_hba *hisi_hba, > struct sbitmap *slot_index_tags = &hisi_hba->slot_index_tags; > int index; > > + if (expose_mq_experimental) > + return sbitmap_get(slot_index_tags, > + hisi_hba->sbitmap_alloc_hint, false); > + > if (scmd) > return scmd->request->tag; > > @@ -583,7 +597,10 @@ static void slot_index_free_v3_hw(struct hisi_hba *hisi_hba, int slot_idx) > { > struct sbitmap *slot_index_tags = &hisi_hba->slot_index_tags; > > - if (slot_idx >= HISI_SAS_UNRESERVED_IPTT) > + if (expose_mq_experimental) { > + sbitmap_clear_bit(slot_index_tags, slot_idx); > + hisi_hba->sbitmap_alloc_hint = slot_idx; > + } else if (slot_idx >= HISI_SAS_UNRESERVED_IPTT) > sbitmap_clear_bit(slot_index_tags, > slot_idx - HISI_SAS_UNRESERVED_IPTT); > } > @@ -2414,8 +2431,9 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba) > struct device *dev = hisi_hba->dev; > int vectors; > int max_msi = HISI_SAS_MSI_COUNT_V3_HW, min_msi; > + struct Scsi_Host *shost = hisi_hba->shost; > > - if (auto_affine_msi_experimental) { > + if (auto_affine_msi_experimental || expose_mq_experimental) { > struct irq_affinity desc = { > .pre_vectors = BASE_VECTORS_V3_HW, > }; > @@ -2434,7 +2452,9 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba) > &desc); > if (vectors < 0) > return -ENOENT; > - setup_reply_map_v3_hw(hisi_hba, vectors - BASE_VECTORS_V3_HW); > + if (auto_affine_msi_experimental) > + setup_reply_map_v3_hw(hisi_hba, > + vectors - BASE_VECTORS_V3_HW); > } else { > min_msi = max_msi; > vectors = pci_alloc_irq_vectors(hisi_hba->pci_dev, min_msi, > @@ -2444,6 +2464,9 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba) > } > > hisi_hba->cq_nvecs = vectors - BASE_VECTORS_V3_HW; > + if (expose_mq_experimental) > + shost->nr_hw_queues = hisi_hba->cq_nvecs; > + > return 0; > } > > @@ -3096,6 +3119,17 @@ static int debugfs_set_bist_v3_hw(struct hisi_hba *hisi_hba, bool enable) > return 0; > } > > +static int hisi_sas_map_queues(struct Scsi_Host *shost) > +{ > + struct hisi_hba *hisi_hba = shost_priv(shost); > + struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT]; > + > + if (expose_mq_experimental) > + return blk_mq_pci_map_queues(qmap, hisi_hba->pci_dev, > + BASE_VECTORS_V3_HW); > + return blk_mq_map_queues(qmap); > +} > + > static struct scsi_host_template sht_v3_hw = { > .name = DRV_NAME, > .module = THIS_MODULE, > @@ -3104,6 +3138,7 @@ static struct scsi_host_template sht_v3_hw = { > .slave_configure = hisi_sas_slave_configure, > .scan_finished = hisi_sas_scan_finished, > .scan_start = hisi_sas_scan_start, > + .map_queues = hisi_sas_map_queues, > .change_queue_depth = sas_change_queue_depth, > .bios_param = sas_bios_param, > .this_id = -1, > @@ -3265,8 +3300,14 @@ hisi_sas_v3_probe(struct pci_dev *pdev, const struct pci_device_id *id) > shost->max_lun = ~0; > shost->max_channel = 1; > shost->max_cmd_len = 16; > - shost->can_queue = HISI_SAS_UNRESERVED_IPTT; > - shost->cmd_per_lun = HISI_SAS_UNRESERVED_IPTT; > + > + if (expose_mq_experimental) { > + shost->can_queue = HISI_SAS_MAX_COMMANDS; > + shost->cmd_per_lun = HISI_SAS_MAX_COMMANDS; The above is contradictory with current 'nr_hw_queues''s meaning, see commit on Scsi_Host.nr_hw_queues. /* * In scsi-mq mode, the number of hardware queues supported by the LLD. * * Note: it is assumed that each hardware queue has a queue depth of * can_queue. In other words, the total queue depth per host * is nr_hw_queues * can_queue. */ Also this implementation wastes memory too much. thanks, Ming
On 27/10/2019 08:19, Ming Lei wrote: >> .this_id = -1, >> @@ -3265,8 +3300,14 @@ hisi_sas_v3_probe(struct pci_dev *pdev, const struct pci_device_id *id) >> shost->max_lun = ~0; >> shost->max_channel = 1; >> shost->max_cmd_len = 16; >> - shost->can_queue = HISI_SAS_UNRESERVED_IPTT; >> - shost->cmd_per_lun = HISI_SAS_UNRESERVED_IPTT; >> + Hi Ming, I mentioned in the thread "blk-mq: improvement on handling IO during CPU hotplug" that I was using this series to test that patchset. So just with this patchset (and without yours), I get what looks like some IO errors in the LLDD. The error is an underflow error. I can't figure out what is the cause. I'm wondering if the SCSI command is getting corrupted someway. >> + if (expose_mq_experimental) { >> + shost->can_queue = HISI_SAS_MAX_COMMANDS; >> + shost->cmd_per_lun = HISI_SAS_MAX_COMMANDS; > The above is contradictory with current 'nr_hw_queues''s meaning, > see commit on Scsi_Host.nr_hw_queues. > Right, so I am generating the hostwide tag in the LLDD. And the Scsi host-wide host_busy counter should ensure that we don't pump too much IO to the HBA. What other problem will this cause? Thanks, John > > /* > * In scsi-mq mode, the number of hardware queues supported by the LLD. > * > * Note: it is assumed that each hardware queue has a queue depth of > * can_queue. In other words, the total queue depth per host > * is nr_hw_queues * can_queue. > */ > > Also this implementation wastes memory too much. > > > thanks, > Ming
On Mon, Nov 11, 2019 at 02:02:27PM +0000, John Garry wrote: > On 27/10/2019 08:19, Ming Lei wrote: > > > .this_id = -1, > > > @@ -3265,8 +3300,14 @@ hisi_sas_v3_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > > shost->max_lun = ~0; > > > shost->max_channel = 1; > > > shost->max_cmd_len = 16; > > > - shost->can_queue = HISI_SAS_UNRESERVED_IPTT; > > > - shost->cmd_per_lun = HISI_SAS_UNRESERVED_IPTT; > > > + > > Hi Ming, > > I mentioned in the thread "blk-mq: improvement on handling IO during CPU > hotplug" that I was using this series to test that patchset. > > So just with this patchset (and without yours), I get what looks like some > IO errors in the LLDD. The error is an underflow error. I can't figure out > what is the cause. Can you post the error log? Or interpret the 'underflow error' from hisi sas or scsi viewpoint? > > I'm wondering if the SCSI command is getting corrupted someway. Why do you think the command is corrupted? > > > > + if (expose_mq_experimental) { > > > + shost->can_queue = HISI_SAS_MAX_COMMANDS; > > > + shost->cmd_per_lun = HISI_SAS_MAX_COMMANDS; > > The above is contradictory with current 'nr_hw_queues''s meaning, > > see commit on Scsi_Host.nr_hw_queues. > > > > Right, so I am generating the hostwide tag in the LLDD. And the Scsi > host-wide host_busy counter should ensure that we don't pump too much IO to > the HBA. Even without the host-wide host_busy, your approach should work if you build the hisi sas tag correctly(uniquely), just not efficiently. I'd suggest you to collect trace and observe if request with expected hisi sas tag is sent to hardware. BTW, the patch of 'scsi: core: avoid host-wide host_busy counter for scsi_mq' will be merged to v5.5 if everything is fine. https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git/commit/?h=5.5/scsi-queue&id=6eb045e092efefafc6687409a6fa6d1dabf0fb69 Thanks, Ming
diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h index 4eb8f1c53f78..884f2426d753 100644 --- a/drivers/scsi/hisi_sas/hisi_sas.h +++ b/drivers/scsi/hisi_sas/hisi_sas.h @@ -8,6 +8,8 @@ #define _HISI_SAS_H_ #include <linux/acpi.h> +#include <linux/blk-mq.h> +#include <linux/blk-mq-pci.h> #include <linux/clk.h> #include <linux/debugfs.h> #include <linux/dmapool.h> diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c index 53802c1cc1d0..c8c96a46acfd 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_main.c +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c @@ -389,9 +389,11 @@ static int hisi_sas_task_prep(struct sas_task *task, struct hisi_sas_slot *slot; struct hisi_sas_cmd_hdr *cmd_hdr_base; struct asd_sas_port *sas_port = device->port; + struct Scsi_Host *shost = hisi_hba->shost; struct device *dev = hisi_hba->dev; int dlvry_queue_slot, dlvry_queue, rc, slot_idx; int n_elem = 0, n_elem_dif = 0, n_elem_req = 0; + struct scsi_cmnd *scmd = NULL; struct hisi_sas_dq *dq; unsigned long flags; int wr_q_index; @@ -407,13 +409,38 @@ static int hisi_sas_task_prep(struct sas_task *task, return -ECOMM; } - if (hisi_hba->reply_map) { - int cpu = raw_smp_processor_id(); - unsigned int dq_index = hisi_hba->reply_map[cpu]; + if (task->uldd_task) { + struct ata_queued_cmd *qc; - *dq_pointer = dq = &hisi_hba->dq[dq_index]; - } else { + if (dev_is_sata(device)) { + qc = task->uldd_task; + scmd = qc->scsicmd; + } else { + scmd = task->uldd_task; + } + } + + /* We have to move to just a single mode: expose multiple queues */ + if (!hisi_hba->reply_map && !shost->nr_hw_queues) { *dq_pointer = dq = sas_dev->dq; + } else { + if (hisi_hba->reply_map) { + int cpu = raw_smp_processor_id(); + unsigned int dq_index = hisi_hba->reply_map[cpu]; + + *dq_pointer = dq = &hisi_hba->dq[dq_index]; + } else { + if (scmd) { + unsigned int dq_index; + u32 blk_tag; + + blk_tag = blk_mq_unique_tag(scmd->request); + dq_index = blk_mq_unique_tag_to_hwq(blk_tag); + *dq_pointer = dq = &hisi_hba->dq[dq_index]; + } else { + *dq_pointer = dq = sas_dev->dq; + } + } } port = to_hisi_sas_port(sas_port); @@ -438,22 +465,10 @@ static int hisi_sas_task_prep(struct sas_task *task, } if (hisi_hba->hw->slot_index_alloc) - rc = hisi_hba->hw->slot_index_alloc(hisi_hba, device, NULL); - else { - struct scsi_cmnd *scsi_cmnd = NULL; - - if (task->uldd_task) { - struct ata_queued_cmd *qc; + rc = hisi_hba->hw->slot_index_alloc(hisi_hba, device, scmd); + else + rc = hisi_sas_slot_index_alloc(hisi_hba, scmd); - if (dev_is_sata(device)) { - qc = task->uldd_task; - scsi_cmnd = qc->scsicmd; - } else { - scsi_cmnd = task->uldd_task; - } - } - rc = hisi_sas_slot_index_alloc(hisi_hba, scsi_cmnd); - } if (rc < 0) goto err_out_dif_dma_unmap; diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c index 29119d0b27a7..03ba0416f910 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c +++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c @@ -512,6 +512,11 @@ module_param(auto_affine_msi_experimental, bool, 0444); MODULE_PARM_DESC(auto_affine_msi_experimental, "Enable auto-affinity of MSI IRQs as experimental:\n" "default is off"); +static bool expose_mq_experimental; +module_param(expose_mq_experimental, bool, 0444); +MODULE_PARM_DESC(expose_mq_experimental, "Expose multiple hw queues to upper layer as experimental:\n" + "default is off"); + static u32 hisi_sas_read32(struct hisi_hba *hisi_hba, u32 off) { void __iomem *regs = hisi_hba->regs + off; @@ -558,6 +563,11 @@ static u32 hisi_sas_phy_read32(struct hisi_hba *hisi_hba, static int bitmaps_alloc_v3_hw(struct hisi_hba *hisi_hba) { + if (expose_mq_experimental) + return sbitmap_init_node(&hisi_hba->slot_index_tags, + HISI_SAS_MAX_COMMANDS, -1, + GFP_KERNEL, + dev_to_node(hisi_hba->dev)); return sbitmap_init_node(&hisi_hba->slot_index_tags, HISI_SAS_UNRESERVED_IPTT, -1, GFP_KERNEL, dev_to_node(hisi_hba->dev)); @@ -570,6 +580,10 @@ static int slot_index_alloc_v3_hw(struct hisi_hba *hisi_hba, struct sbitmap *slot_index_tags = &hisi_hba->slot_index_tags; int index; + if (expose_mq_experimental) + return sbitmap_get(slot_index_tags, + hisi_hba->sbitmap_alloc_hint, false); + if (scmd) return scmd->request->tag; @@ -583,7 +597,10 @@ static void slot_index_free_v3_hw(struct hisi_hba *hisi_hba, int slot_idx) { struct sbitmap *slot_index_tags = &hisi_hba->slot_index_tags; - if (slot_idx >= HISI_SAS_UNRESERVED_IPTT) + if (expose_mq_experimental) { + sbitmap_clear_bit(slot_index_tags, slot_idx); + hisi_hba->sbitmap_alloc_hint = slot_idx; + } else if (slot_idx >= HISI_SAS_UNRESERVED_IPTT) sbitmap_clear_bit(slot_index_tags, slot_idx - HISI_SAS_UNRESERVED_IPTT); } @@ -2414,8 +2431,9 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba) struct device *dev = hisi_hba->dev; int vectors; int max_msi = HISI_SAS_MSI_COUNT_V3_HW, min_msi; + struct Scsi_Host *shost = hisi_hba->shost; - if (auto_affine_msi_experimental) { + if (auto_affine_msi_experimental || expose_mq_experimental) { struct irq_affinity desc = { .pre_vectors = BASE_VECTORS_V3_HW, }; @@ -2434,7 +2452,9 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba) &desc); if (vectors < 0) return -ENOENT; - setup_reply_map_v3_hw(hisi_hba, vectors - BASE_VECTORS_V3_HW); + if (auto_affine_msi_experimental) + setup_reply_map_v3_hw(hisi_hba, + vectors - BASE_VECTORS_V3_HW); } else { min_msi = max_msi; vectors = pci_alloc_irq_vectors(hisi_hba->pci_dev, min_msi, @@ -2444,6 +2464,9 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba) } hisi_hba->cq_nvecs = vectors - BASE_VECTORS_V3_HW; + if (expose_mq_experimental) + shost->nr_hw_queues = hisi_hba->cq_nvecs; + return 0; } @@ -3096,6 +3119,17 @@ static int debugfs_set_bist_v3_hw(struct hisi_hba *hisi_hba, bool enable) return 0; } +static int hisi_sas_map_queues(struct Scsi_Host *shost) +{ + struct hisi_hba *hisi_hba = shost_priv(shost); + struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT]; + + if (expose_mq_experimental) + return blk_mq_pci_map_queues(qmap, hisi_hba->pci_dev, + BASE_VECTORS_V3_HW); + return blk_mq_map_queues(qmap); +} + static struct scsi_host_template sht_v3_hw = { .name = DRV_NAME, .module = THIS_MODULE, @@ -3104,6 +3138,7 @@ static struct scsi_host_template sht_v3_hw = { .slave_configure = hisi_sas_slave_configure, .scan_finished = hisi_sas_scan_finished, .scan_start = hisi_sas_scan_start, + .map_queues = hisi_sas_map_queues, .change_queue_depth = sas_change_queue_depth, .bios_param = sas_bios_param, .this_id = -1, @@ -3265,8 +3300,14 @@ hisi_sas_v3_probe(struct pci_dev *pdev, const struct pci_device_id *id) shost->max_lun = ~0; shost->max_channel = 1; shost->max_cmd_len = 16; - shost->can_queue = HISI_SAS_UNRESERVED_IPTT; - shost->cmd_per_lun = HISI_SAS_UNRESERVED_IPTT; + + if (expose_mq_experimental) { + shost->can_queue = HISI_SAS_MAX_COMMANDS; + shost->cmd_per_lun = HISI_SAS_MAX_COMMANDS; + } else { + shost->can_queue = HISI_SAS_UNRESERVED_IPTT; + shost->cmd_per_lun = HISI_SAS_UNRESERVED_IPTT; + } sha->sas_ha_name = DRV_NAME; sha->dev = dev;
Since we're not ready to expose mutliple queues to the upper layer always due to CPU hotplug issue, add a new interim experimental command line option to support it. We still need to keep supporting auto_affine_msi_experimental, since people are now replying the performance it provides, even though it is unsafe. If auto_affine_msi_experimental and expose_mq_experimental are both set, then auto_affine_msi_experimental takes preference. Signed-off-by: John Garry <john.garry@huawei.com> --- drivers/scsi/hisi_sas/hisi_sas.h | 2 + drivers/scsi/hisi_sas/hisi_sas_main.c | 55 ++++++++++++++++---------- drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 51 +++++++++++++++++++++--- 3 files changed, 83 insertions(+), 25 deletions(-) -- 2.17.1