RE: [PATCH 4/5] megaraid_sas: scsi-mq support

[Sumit Saxena <sumit.saxena@broadcom.com>]

>-----Original Message-----
>From: linux-scsi-owner@vger.kernel.org [mailto:linux-scsi-
>owner@vger.kernel.org] On Behalf Of Hannes Reinecke
>Sent: Friday, November 11, 2016 3:15 PM
>To: Martin K. Petersen
>Cc: Christoph Hellwig; James Bottomley; Sumit Saxena; linux-
>scsi@vger.kernel.org; Hannes Reinecke; Hannes Reinecke
>Subject: [PATCH 4/5] megaraid_sas: scsi-mq support
>
>This patch enables full scsi multiqueue support. But as I have been
seeing
>performance regressions I've also added a module parameter 'use_blk_mq',
>allowing multiqueue to be switched off if required.

I may need sometime to comment on this patch. I will have some performance
runs with this patch. Can you share your test configuration details?

Thanks,
Sumit
>
>Signed-off-by: Hannes Reinecke <hare@suse.com>
>---
> drivers/scsi/megaraid/megaraid_sas_base.c   | 22 +++++++++++++++++
> drivers/scsi/megaraid/megaraid_sas_fusion.c | 38
>+++++++++++++++++++++--------
> 2 files changed, 50 insertions(+), 10 deletions(-)
>
>diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c
>b/drivers/scsi/megaraid/megaraid_sas_base.c
>index d580406..1af47e6 100644
>--- a/drivers/scsi/megaraid/megaraid_sas_base.c
>+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
>@@ -48,6 +48,7 @@
> #include <linux/blkdev.h>
> #include <linux/mutex.h>
> #include <linux/poll.h>
>+#include <linux/blk-mq-pci.h>
>
> #include <scsi/scsi.h>
> #include <scsi/scsi_cmnd.h>
>@@ -104,6 +105,9 @@
> module_param(scmd_timeout, int, S_IRUGO);
>MODULE_PARM_DESC(scmd_timeout, "scsi command timeout (10-90s), default
>90s. See megasas_reset_timer.");
>
>+bool use_blk_mq = true;
>+module_param_named(use_blk_mq, use_blk_mq, bool, 0);
>+
> MODULE_LICENSE("GPL");
> MODULE_VERSION(MEGASAS_VERSION);
> MODULE_AUTHOR("megaraidlinux.pdl@avagotech.com");
>@@ -1882,6 +1886,17 @@ static void megasas_slave_destroy(struct
scsi_device
>*sdev)
> 	sdev->hostdata = NULL;
> }
>
>+static int megasas_map_queues(struct Scsi_Host *shost) {
>+	struct megasas_instance *instance = (struct megasas_instance *)
>+		shost->hostdata;
>+
>+	if (!instance->ctrl_context)
>+		return 0;
>+
>+	return blk_mq_pci_map_queues(&shost->tag_set, instance->pdev, 0);
}
>+
> /*
> * megasas_complete_outstanding_ioctls - Complete outstanding ioctls
after a
> *                                       kill adapter
>@@ -2986,6 +3001,7 @@ struct device_attribute *megaraid_host_attrs[] = {
> 	.slave_configure = megasas_slave_configure,
> 	.slave_alloc = megasas_slave_alloc,
> 	.slave_destroy = megasas_slave_destroy,
>+	.map_queues = megasas_map_queues,
> 	.queuecommand = megasas_queue_command,
> 	.eh_target_reset_handler = megasas_reset_target,
> 	.eh_abort_handler = megasas_task_abort, @@ -5610,6 +5626,12 @@
>static int megasas_io_attach(struct megasas_instance *instance)
> 	host->max_id = MEGASAS_MAX_DEV_PER_CHANNEL;
> 	host->max_lun = MEGASAS_MAX_LUN;
> 	host->max_cmd_len = 16;
>+	host->nr_hw_queues = instance->msix_vectors ?
>+		instance->msix_vectors : 1;
>+	if (use_blk_mq) {
>+		host->can_queue = instance->max_scsi_cmds /
>host->nr_hw_queues;
>+		host->use_blk_mq = 1;
>+	}
>
> 	/*
> 	 * Notify the mid-layer about the new controller diff --git
>a/drivers/scsi/megaraid/megaraid_sas_fusion.c
>b/drivers/scsi/megaraid/megaraid_sas_fusion.c
>index eb3cb0f..aba53c0 100644
>--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
>+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
>@@ -1703,6 +1703,7 @@ static int megasas_create_sg_sense_fusion(struct
>megasas_instance *instance)
> 	struct IO_REQUEST_INFO io_info;
> 	struct fusion_context *fusion;
> 	struct MR_DRV_RAID_MAP_ALL *local_map_ptr;
>+	u16 msix_index;
> 	u8 *raidLUN;
>
> 	device_id = MEGASAS_DEV_INDEX(scp);
>@@ -1792,11 +1793,13 @@ static int megasas_create_sg_sense_fusion(struct
>megasas_instance *instance)
> 			fp_possible = io_info.fpOkForIo;
> 	}
>
>-	/* Use raw_smp_processor_id() for now until cmd->request->cpu is
>CPU
>-	   id by default, not CPU group id, otherwise all MSI-X queues
>won't
>-	   be utilized */
>-	cmd->request_desc->SCSIIO.MSIxIndex = instance->msix_vectors ?
>-		raw_smp_processor_id() % instance->msix_vectors : 0;
>+	if (shost_use_blk_mq(instance->host)) {
>+		u32 blk_tag = blk_mq_unique_tag(scp->request);
>+		msix_index = blk_mq_unique_tag_to_hwq(blk_tag);
>+	} else
>+		msix_index = instance->msix_vectors ?
>+			raw_smp_processor_id() % instance->msix_vectors :
>0;
>+	cmd->request_desc->SCSIIO.MSIxIndex = msix_index;
>
> 	if (fp_possible) {
> 		megasas_set_pd_lba(io_request, scp->cmd_len, &io_info,
scp,
>@@ -1971,6 +1974,7 @@ static void megasas_build_ld_nonrw_fusion(struct
>megasas_instance *instance,
> 	struct RAID_CONTEXT	*pRAID_Context;
> 	struct MR_PD_CFG_SEQ_NUM_SYNC *pd_sync;
> 	struct fusion_context *fusion = instance->ctrl_context;
>+	u16 msix_index;
> 	pd_sync = (void *)fusion->pd_seq_sync[(instance->pd_seq_map_id -
>1) & 1];
>
> 	device_id = MEGASAS_DEV_INDEX(scmd);
>@@ -2013,11 +2017,14 @@ static void megasas_build_ld_nonrw_fusion(struct
>megasas_instance *instance,
> 		io_request->DevHandle = cpu_to_le16(0xFFFF);
> 	}
>
>+	if (shost_use_blk_mq(instance->host)) {
>+		u32 blk_tag = blk_mq_unique_tag(scmd->request);
>+		msix_index = blk_mq_unique_tag_to_hwq(blk_tag);
>+	} else
>+		msix_index = instance->msix_vectors ?
>+			(raw_smp_processor_id() % instance->msix_vectors)
>: 0;
>+	cmd->request_desc->SCSIIO.MSIxIndex = msix_index;
> 	cmd->request_desc->SCSIIO.DevHandle = io_request->DevHandle;
>-	cmd->request_desc->SCSIIO.MSIxIndex =
>-		instance->msix_vectors ?
>-		(raw_smp_processor_id() % instance->msix_vectors) : 0;
>-
>
> 	if (!fp_possible) {
> 		/* system pd firmware path */
>@@ -2188,7 +2195,18 @@ static void megasas_build_ld_nonrw_fusion(struct
>megasas_instance *instance,
> 		return SCSI_MLQUEUE_DEVICE_BUSY;
> 	}
>
>-	cmd = megasas_get_cmd_fusion(instance, scmd->request->tag);
>+	if (shost_use_blk_mq(instance->host)) {
>+		int msix_vectors, hwq_size;
>+		u32 blk_tag = blk_mq_unique_tag(scmd->request);
>+		u16 hwq = blk_mq_unique_tag_to_hwq(blk_tag);
>+		u16 tag = blk_mq_unique_tag_to_tag(blk_tag);
>+
>+		msix_vectors = instance->msix_vectors ?
>+			instance->msix_vectors : 1;
>+		hwq_size = instance->max_scsi_cmds / msix_vectors;
>+		cmd = megasas_get_cmd_fusion(instance, (hwq * hwq_size) +
>tag);
>+	} else
>+		cmd = megasas_get_cmd_fusion(instance,
>scmd->request->tag);
>
> 	index = cmd->index;
>
>--
>1.8.5.6
>
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