Re: [PATCH v2] aacraid: reply queue mapping to CPUs based of IRQ affinity

On 28/04/2023 22:07, Sagar Biradar wrote:

Fix the IO hang that arises because of MSIx vector not having a mapped online CPU upon receiving completion. This patch sets up a reply queue mapping to CPUs based on the IRQ affinity retrieved using pci_irq_get_affinity() API.

aac_setup_reply_map() is an explicit mapping for internally generated (non-SCSI) cmds. The SCSI cmds take the blk_mq route, and the non-SCSI cmds are mapped to the reply_map.

This now looks better.

I would still prefer if no reply_map was used even for internal commands. As I see, you have two alternatives (to using reply_map): - instead of using a driver-internal reply_map, lookup CPU->HW queue mapping for internal commands by using shost->tag_set.map[HCTX_TYPE_DEFAULT].mq_map[raw_smp_processor_id()] Ideally when we finally support reserved commands for SCSI ML we will have a better solution for this. - if it is possible to send driver internal commands on a specific HW queue always, then reserve a dedicated HW queue for them (and always send on that HW queue). You may reserve this HW queue by omitting 1x HW queue from pci_alloc_irq_vectors_affinity() for affinity spread

Reviewed-by: Gilbert Wu gilbert.wu@microchip.com Signed-off-by: Sagar Biradar Sagar.Biradar@microchip.com

---

drivers/scsi/aacraid/aacraid.h | 1 + drivers/scsi/aacraid/comminit.c | 32 ++++++++++++++++++++++++++++++++ drivers/scsi/aacraid/commsup.c | 6 +++++- drivers/scsi/aacraid/linit.c | 25 +++++++++++++++++++++++++ drivers/scsi/aacraid/src.c | 13 +++++++++++-- 5 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h index 5e115e8b2ba4..20f8560a3038 100644 --- a/drivers/scsi/aacraid/aacraid.h +++ b/drivers/scsi/aacraid/aacraid.h @@ -1678,6 +1678,7 @@ struct aac_dev u32 handle_pci_error; bool init_reset; u8 soft_reset_support;

• unsigned int *reply_map; };

#define aac_adapter_interrupt(dev) \ diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c index bd99c5492b7d..6f4e40cdaade 100644 --- a/drivers/scsi/aacraid/comminit.c +++ b/drivers/scsi/aacraid/comminit.c @@ -33,6 +33,8 @@ #include "aacraid.h" +void aac_setup_reply_map(struct aac_dev *dev);

• struct aac_common aac_config = { .irq_mod = 1 };

@@ -630,6 +632,9 @@ struct aac_dev *aac_init_adapter(struct aac_dev *dev) if (aac_is_src(dev)) aac_define_int_mode(dev);

• aac_setup_reply_map(dev);
• /*
  • Ok now init the communication subsystem
  */

@@ -658,3 +663,30 @@ struct aac_dev *aac_init_adapter(struct aac_dev *dev) return dev; } +/*

• • aac_setup_reply_map - This is an explicit mapping for
• • internally generated (non-SCSI) cmds which need to be
• • serviced outside of IO requests.
• • The SCSI cmds take the blk_mq mechanism,
• • and the non-SCSI cmds are mapped to the reply_map.
• */

+void aac_setup_reply_map(struct aac_dev *dev) +{

• const struct cpumask *mask;
• unsigned int i, cpu = 1;
• for (i = 1; i < dev->max_msix; i++) {

• mask = pci_irq_get_affinity(dev->pdev, i);
  

• if (!mask)
  

• 	goto fallback;
  

• for_each_cpu(cpu, mask) {
  

• 	dev->reply_map[cpu] = i;
  

• }
  

• }
• return;

+fallback:

• for_each_possible_cpu(cpu)

• dev->reply_map[cpu] = 0;
  

+} diff --git a/drivers/scsi/aacraid/commsup.c b/drivers/scsi/aacraid/commsup.c index deb32c9f4b3e..3f062e4013ab 100644 --- a/drivers/scsi/aacraid/commsup.c +++ b/drivers/scsi/aacraid/commsup.c @@ -223,8 +223,12 @@ int aac_fib_setup(struct aac_dev * dev) struct fib *aac_fib_alloc_tag(struct aac_dev *dev, struct scsi_cmnd *scmd) { struct fib *fibptr;

• u32 blk_tag;
• int i;

• fibptr = &dev->fibs[scsi_cmd_to_rq(scmd)->tag];

• blk_tag = blk_mq_unique_tag(scsi_cmd_to_rq(scmd));
• i = blk_mq_unique_tag_to_tag(blk_tag);
• fibptr = &dev->fibs[i]; /*
  • Null out fields that depend on being zero at the start of
  • each I/O

diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c index 5ba5c18b77b4..077adbcde909 100644 --- a/drivers/scsi/aacraid/linit.c +++ b/drivers/scsi/aacraid/linit.c @@ -34,6 +34,7 @@ #include <linux/delay.h> #include <linux/kthread.h> #include <linux/msdos_partition.h> +#include <linux/blk-mq-pci.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> @@ -505,6 +506,16 @@ static int aac_slave_configure(struct scsi_device *sdev) return 0; } +static void aac_map_queues(struct Scsi_Host *shost) +{

• struct aac_dev *aac = (struct aac_dev *)shost->hostdata;

I don't think that you need a explicit casting ...

• blk_mq_pci_map_queues(&shost->tag_set.map[HCTX_TYPE_DEFAULT],

• 		aac->pdev, 0);
  

+}

• /**
  • aac_change_queue_depth - alter queue depths
  • @sdev: SCSI device we are considering

@@ -1489,6 +1500,7 @@ static struct scsi_host_template aac_driver_template = { .bios_param = aac_biosparm, .shost_groups = aac_host_groups, .slave_configure = aac_slave_configure,

• .map_queues = aac_map_queues, .change_queue_depth = aac_change_queue_depth, .sdev_groups = aac_dev_groups, .eh_abort_handler = aac_eh_abort,

@@ -1668,6 +1680,14 @@ static int aac_probe_one(struct pci_dev *pdev, const struct pci_device_id *id) goto out_free_host; }

• aac->reply_map = kzalloc(sizeof(unsigned int) * nr_cpu_ids,

• 		GFP_KERNEL);
  

• if (!aac->reply_map) {

• error = -ENOMEM;
  

• dev_err(&pdev->dev, "reply_map allocation failed\n");
  

• goto out_free_host;
  

• }
• spin_lock_init(&aac->fib_lock);

mutex_init(&aac->ioctl_mutex); @@ -1776,6 +1796,8 @@ static int aac_probe_one(struct pci_dev *pdev, const struct pci_device_id *id) shost->max_lun = AAC_MAX_LUN; pci_set_drvdata(pdev, shost);

• shost->nr_hw_queues = aac->max_msix;
• shost->host_tagset = 1;

error = scsi_add_host(shost, &pdev->dev); if (error) @@ -1797,6 +1819,8 @@ static int aac_probe_one(struct pci_dev *pdev, const struct pci_device_id *id) aac->comm_addr, aac->comm_phys); kfree(aac->queues); aac_adapter_ioremap(aac, 0);

• /* By now we should have configured the reply_map */
• kfree(aac->reply_map); kfree(aac->fibs); kfree(aac->fsa_dev); out_free_host:

@@ -1918,6 +1942,7 @@ static void aac_remove_one(struct pci_dev *pdev) aac_adapter_ioremap(aac, 0);

• kfree(aac->reply_map); kfree(aac->fibs); kfree(aac->fsa_dev);

diff --git a/drivers/scsi/aacraid/src.c b/drivers/scsi/aacraid/src.c index 11ef58204e96..46c0f4df995d 100644 --- a/drivers/scsi/aacraid/src.c +++ b/drivers/scsi/aacraid/src.c @@ -493,6 +493,8 @@ static int aac_src_deliver_message(struct fib *fib) #endif u16 vector_no;

• struct scsi_cmnd *scmd;
• u32 blk_tag;

atomic_inc(&q->numpending); @@ -505,8 +507,15 @@ static int aac_src_deliver_message(struct fib *fib) if ((dev->comm_interface == AAC_COMM_MESSAGE_TYPE3) && dev->sa_firmware) vector_no = aac_get_vector(dev);

• else
  

• 	vector_no = fib->vector_no;
  

• else {
  

• 	if (!fib->vector_no || !fib->callback_data) {
  

• 		vector_no = dev->reply_map[raw_smp_processor_id()];
  

• 	} else {
  

• 		scmd = (struct scsi_cmnd *)fib->callback_data;
  

• 		blk_tag = blk_mq_unique_tag(scsi_cmd_to_rq(scmd));
  

• 		vector_no = blk_mq_unique_tag_to_hwq(blk_tag);
  

• 	}
  

• }
  

if (native_hba) { if (fib->flags & FIB_CONTEXT_FLAG_NATIVE_HBA_TMF) {