Re: [PATCH v4] aacraid: reply queue mapping to CPUs based of IRQ affinity

On 20/05/2023 00:08, Sagar Biradar wrote:

Fix the IO hang that arises because of MSIx vector not having a mapped online CPU upon receiving completion.

The SCSI cmds take the blk_mq route, which is setup during the init. The reserved cmds fetch the vector_no from mq_map after the init is complete and before the init, they use 0 - as per the norm.

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

This the patch which seems to be causing the issue in https://bugzilla.kernel.org/show_bug.cgi?id=217599

I will comment here since I got no response there...

---

drivers/scsi/aacraid/aacraid.h | 1 + drivers/scsi/aacraid/comminit.c | 1 - drivers/scsi/aacraid/commsup.c | 6 +++++- drivers/scsi/aacraid/linit.c | 14 ++++++++++++++ drivers/scsi/aacraid/src.c | 25 +++++++++++++++++++++++-- 5 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h index 5e115e8b2ba4..7c6efde75da6 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;

• u8 use_map_queue; };

#define aac_adapter_interrupt(dev) \ diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c index bd99c5492b7d..a5483e7e283a 100644 --- a/drivers/scsi/aacraid/comminit.c +++ b/drivers/scsi/aacraid/comminit.c @@ -657,4 +657,3 @@ struct aac_dev *aac_init_adapter(struct aac_dev *dev) return dev; }

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..9caf8c314ce1 100644 --- a/drivers/scsi/aacraid/linit.c +++ b/drivers/scsi/aacraid/linit.c @@ -19,6 +19,7 @@ #include <linux/compat.h> #include <linux/blkdev.h> +#include <linux/blk-mq-pci.h> #include <linux/completion.h> #include <linux/init.h> #include <linux/interrupt.h> @@ -505,6 +506,15 @@ 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;
• blk_mq_pci_map_queues(&shost->tag_set.map[HCTX_TYPE_DEFAULT],

• 		aac->pdev, 0);
  

• aac->use_map_queue = true;

+}

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

@@ -1489,6 +1499,7 @@ 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,

@@ -1776,6 +1787,8 @@ 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) @@ -1908,6 +1921,7 @@ static void aac_remove_one(struct pci_dev *pdev) struct aac_dev *aac = (struct aac_dev *)shost->hostdata; aac_cancel_rescan_worker(aac);

• aac->use_map_queue = false; scsi_remove_host(shost);

__aac_shutdown(aac); diff --git a/drivers/scsi/aacraid/src.c b/drivers/scsi/aacraid/src.c index 11ef58204e96..61949f374188 100644 --- a/drivers/scsi/aacraid/src.c +++ b/drivers/scsi/aacraid/src.c @@ -493,6 +493,10 @@ static int aac_src_deliver_message(struct fib *fib) #endif u16 vector_no;

• struct scsi_cmnd *scmd;
• u32 blk_tag;
• struct Scsi_Host *shost = dev->scsi_host_ptr;
• struct blk_mq_queue_map *qmap;

atomic_inc(&q->numpending); @@ -505,8 +509,25 @@ 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) {
  

• 		if (shost && dev->use_map_queue) {
  

• 			qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT];
  

• 			vector_no = qmap->mq_map[raw_smp_processor_id()];
  

• 		}
  

• 		/*
  

• 		 *	We hardcode the vector_no for
  

• 		 *	reserved commands as a valid shost is
  

• 		 *	absent during the init
  

• 		 */
  

• 		else
  

• 			vector_no = 0;
  

• 	} 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);
  

Hannes' patch in the bugzilla was to revert to using hw queue #0 always for internal commands, and it didn't help.

Could there be any issue in using hw queue #0 for regular SCSI commands?

AFAICS, that's a significant change. Previously we would use fib->vector_no to decide the queue, which was in range (1, dev->max_msix).

BTW, is there any code which relies on a command being sent/received on the HW queue same as fib->vector_no?

Thanks, John

• }
  

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