Re: [PATCH 2/4] scsi: mpt3sas: use private counter for tracking inflight per-LUN commands

Hannes Reinecke
2019-11-20T09:55:59Z

On 11/18/19 11:31 AM, Ming Lei wrote:
> Prepare for bypassing sdev->device_busy for improving performance on
> fast SCSI storage device, so sdev->device_busy can't be relied
> any more.
>
> mpt3sas may need one such counter for balancing load among LUNs in
> some specific setting, so add one private counter for this purpose.
>
> Cc: Sathya Prakash <sathya.prakash@broadcom.com>
> Cc: Chaitra P B <chaitra.basappa@broadcom.com>
> Cc: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
> Cc: Kashyap Desai <kashyap.desai@broadcom.com>
> Cc: Sumit Saxena <sumit.saxena@broadcom.com>
> Cc: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
> Cc: Ewan D. Milne <emilne@redhat.com>
> Cc: Christoph Hellwig <hch@lst.de>,
> Cc: Hannes Reinecke <hare@suse.de>
> Cc: Bart Van Assche <bart.vanassche@wdc.com>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> drivers/scsi/mpt3sas/mpt3sas_base.c | 3 ++-
> drivers/scsi/mpt3sas/mpt3sas_base.h | 1 +
> drivers/scsi/mpt3sas/mpt3sas_scsih.c | 15 +++++++++++++--
> 3 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
> index fea3cb6a090b..9c2d374b3157 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_base.c
> +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
> @@ -3480,12 +3480,13 @@ static inline u8
> _base_get_high_iops_msix_index(struct MPT3SAS_ADAPTER *ioc,
> struct scsi_cmnd *scmd)
> {
> + struct MPT3SAS_DEVICE *sas_device_priv_data = scmd->device->hostdata;
> /**
> * Round robin the IO interrupts among the high iops
> * reply queues in terms of batch count 16 when outstanding
> * IOs on the target device is >=8.
> */
> - if (atomic_read(&scmd->device->device_busy) >
> + if (atomic_read(&sas_device_priv_data->active_cmds) >
> MPT3SAS_DEVICE_HIGH_IOPS_DEPTH)
> return base_mod64((
> atomic64_add_return(1, &ioc->high_iops_outstanding) /
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
> index faca0a5e71f8..9e9f319bb636 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_base.h
> +++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
> @@ -467,6 +467,7 @@ struct MPT3SAS_DEVICE {
> * thing while a SATL command is pending.
> */
> unsigned long ata_command_pending;
> + atomic_t active_cmds;
>
> };
>
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
> index c8e512ba6d39..194960dae1d6 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
> +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
> @@ -1770,6 +1770,7 @@ scsih_slave_alloc(struct scsi_device *sdev)
>
> sas_device_priv_data->lun = sdev->lun;
> sas_device_priv_data->flags = MPT_DEVICE_FLAGS_INIT;
> + atomic_set(&sas_device_priv_data->active_cmds, 0);
>
> starget = scsi_target(sdev);
> sas_target_priv_data = starget->hostdata;
> @@ -2884,6 +2885,7 @@ scsih_abort(struct scsi_cmnd *scmd)
> ioc->remove_host) {
> sdev_printk(KERN_INFO, scmd->device,
> "device been deleted! scmd(%p)\n", scmd);
> + atomic_dec(&sas_device_priv_data->active_cmds);
> scmd->result = DID_NO_CONNECT << 16;
> scmd->scsi_done(scmd);
> r = SUCCESS;
> @@ -2993,7 +2995,7 @@ scsih_dev_reset(struct scsi_cmnd *scmd)
> MPI2_SCSITASKMGMT_TASKTYPE_LOGICAL_UNIT_RESET, 0, 0,
> tr_timeout, tr_method);
> /* Check for busy commands after reset */
> - if (r == SUCCESS && atomic_read(&scmd->device->device_busy))
> + if (r == SUCCESS && atomic_read(&sas_device_priv_data->active_cmds))
> r = FAILED;
> out:
> sdev_printk(KERN_INFO, scmd->device, "device reset: %s scmd(%p)\n",
> @@ -4517,9 +4519,12 @@ _scsih_flush_running_cmds(struct MPT3SAS_ADAPTER *ioc)
> int count = 0;
>
> for (smid = 1; smid <= ioc->scsiio_depth; smid++) {
> + struct MPT3SAS_DEVICE *sas_device_priv_data;
> +
> scmd = mpt3sas_scsih_scsi_lookup_get(ioc, smid);
> if (!scmd)
> continue;
> + sas_device_priv_data = scmd->device->hostdata;
> count++;
> _scsih_set_satl_pending(scmd, false);
> st = scsi_cmd_priv(scmd);
> @@ -4529,6 +4534,7 @@ _scsih_flush_running_cmds(struct MPT3SAS_ADAPTER *ioc)
> scmd->result = DID_NO_CONNECT << 16;
> else
> scmd->result = DID_RESET << 16;
> + atomic_dec(&sas_device_priv_data->active_cmds);
> scmd->scsi_done(scmd);
> }
> dtmprintk(ioc, ioc_info(ioc, "completing %d cmds\n", count));
> @@ -4756,11 +4762,14 @@ scsih_qcmd(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
> mpi_request->LUN);
> memcpy(mpi_request->CDB.CDB32, scmd->cmnd, scmd->cmd_len);
>
> + atomic_inc(&sas_device_priv_data->active_cmds);
> +
> if (mpi_request->DataLength) {
> pcie_device = sas_target_priv_data->pcie_dev;
> if (ioc->build_sg_scmd(ioc, scmd, smid, pcie_device)) {
> mpt3sas_base_free_smid(ioc, smid);
> _scsih_set_satl_pending(scmd, false);
> + atomic_dec(&sas_device_priv_data->active_cmds);
> goto out;
> }
> } else
> @@ -5207,6 +5216,7 @@ _scsih_smart_predicted_fault(struct MPT3SAS_ADAPTER *ioc, u16 handle)
> static u8
> _scsih_io_done(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index, u32 reply)
> {
> + struct MPT3SAS_DEVICE *sas_device_priv_data;
> Mpi25SCSIIORequest_t *mpi_request;
> Mpi2SCSIIOReply_t *mpi_reply;
> struct scsi_cmnd *scmd;
> @@ -5216,7 +5226,6 @@ _scsih_io_done(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index, u32 reply)
> u8 scsi_state;
> u8 scsi_status;
> u32 log_info;
> - struct MPT3SAS_DEVICE *sas_device_priv_data;
> u32 response_code = 0;
>
> mpi_reply = mpt3sas_base_get_reply_virt_addr(ioc, reply);

The above two modifications are probably not needed ...

> @@ -5225,6 +5234,7 @@ _scsih_io_done(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index, u32 reply)
> if (scmd == NULL)
> return 1;
>
> + sas_device_priv_data = scmd->device->hostdata;
> _scsih_set_satl_pending(scmd, false);
>
> mpi_request = mpt3sas_base_get_msg_frame(ioc, smid);
> @@ -5431,6 +5441,7 @@ _scsih_io_done(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index, u32 reply)
>
> scsi_dma_unmap(scmd);
> mpt3sas_base_free_smid(ioc, smid);
> + atomic_dec(&sas_device_priv_data->active_cmds);
> scmd->scsi_done(scmd);
> return 0;
> }
>
Otherwise:

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
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