Re: [PATCH AUTOSEL 6.1 10/15] scsi: aacraid: Reply queue mapping to CPUs based on IRQ affinity

Linux regression tracking (Thorsten Leemhuis)
2023-09-06T10:10:12Z

On 29.08.23 15:32, Sasha Levin wrote:
> From: Sagar Biradar <sagar.biradar@microchip.com>
>
> [ Upstream commit 9dc704dcc09eae7d21b5da0615eb2ed79278f63e ]
>
> Fix the I/O hang that arises because of the MSIx vector not having a mapped
> online CPU upon receiving completion.

Sasha: you might want to consider dropping this from the 6.1 and 5.15
autosel queues for now, as this commit apparently causes a regression:
https://bugzilla.kernel.org/show_bug.cgi?id=217599

Sagar Biradar: as this is a commit of yours; could you please look into
the report? It was bisected a few weeks ago, but I suspect nobody told
you. Ahh, the joys of bugzilla.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
If I did something stupid, please tell me, as explained on that page.

> SCSI cmds take the blk_mq route, which is setup during init. Reserved cmds
> fetch the vector_no from mq_map after init is complete. Before init, they
> have to use 0 - as per the norm.
>
> Reviewed-by: Gilbert Wu <gilbert.wu@microchip.com>
> Signed-off-by: Sagar Biradar <Sagar.Biradar@microchip.com>
> Reviewed-by: John Garry <john.g.garry@oracle.com>
> Link: https://lore.kernel.org/r/20230519230834.27436-1-sagar.biradar@microchip.com
> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> drivers/scsi/aacraid/aacraid.h | 1 +
> drivers/scsi/aacraid/commsup.c | 6 +++++-
> drivers/scsi/aacraid/linit.c | 14 ++++++++++++++
> drivers/scsi/aacraid/src.c | 25 +++++++++++++++++++++++--
> 4 files changed, 43 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h
> index 5e115e8b2ba46..7c6efde75da66 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/commsup.c b/drivers/scsi/aacraid/commsup.c
> index deb32c9f4b3e6..3f062e4013ab6 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 5ba5c18b77b46..bff49b8ab057d 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 11ef58204e96f..61949f3741886 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);
> + }
> + }
>
> if (native_hba) {
> if (fib->flags & FIB_CONTEXT_FLAG_NATIVE_HBA_TMF) {