Commit 103fbf8e authored by Kashyap Desai's avatar Kashyap Desai Committed by Jens Axboe
Browse files

scsi: megaraid_sas: Added support for shared host tagset for cpuhotplug 



Fusion adapters can steer completions to individual queues, and
we now have support for shared host-wide tags.
So we can enable multiqueue support for fusion adapters.

Once driver enable shared host-wide tags, cpu hotplug feature is also
supported as it was enabled using below patchsets -
commit bf0beec0 ("blk-mq: drain I/O when all CPUs in a hctx are
offline")

Currently driver has provision to disable host-wide tags using
"host_tagset_enable" module parameter.

Once we do not have any major performance regression using host-wide
tags, we will drop the hand-crafted interrupt affinity settings.

Performance is also meeting the expecatation - (used both none and
mq-deadline scheduler)
24 Drive SSD on Aero with/without this patch can get 3.1M IOPs
3 VDs consist of 8 SAS SSD on Aero with/without this patch can get 3.1M
IOPs.

Signed-off-by: default avatarKashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarJohn Garry <john.garry@huawei.com>
Tested-by: default avatarDouglas Gilbert <dgilbert@interlog.com>
Acked-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f7c4cdc7

drivers/scsi/megaraid/megaraid_sas_base.c

+39 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#include <linux/poll.h>

#include <linux/vmalloc.h>

#include <linux/irq_poll.h>

#include <linux/blk-mq-pci.h>



#include <scsi/scsi.h>

#include <scsi/scsi_cmnd.h>
@@ -113,6 +114,10 @@ unsigned int enable_sdev_max_qd; 
module_param(enable_sdev_max_qd, int, 0444);

MODULE_PARM_DESC(enable_sdev_max_qd, "Enable sdev max qd as can_queue. Default: 0");



int host_tagset_enable = 1;

module_param(host_tagset_enable, int, 0444);

MODULE_PARM_DESC(host_tagset_enable, "Shared host tagset enable/disable Default: enable(1)");



MODULE_LICENSE("GPL");

MODULE_VERSION(MEGASAS_VERSION);

MODULE_AUTHOR("megaraidlinux.pdl@broadcom.com");
@@ -3119,6 +3124,19 @@ megasas_bios_param(struct scsi_device *sdev, struct block_device *bdev, 
	return 0;

}



static int megasas_map_queues(struct Scsi_Host *shost)

{

	struct megasas_instance *instance;



	instance = (struct megasas_instance *)shost->hostdata;



	if (shost->nr_hw_queues == 1)

		return 0;



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

			instance->pdev, instance->low_latency_index_start);

}



static void megasas_aen_polling(struct work_struct *work);



/**
@@ -3427,6 +3445,7 @@ static struct scsi_host_template megasas_template = { 
	.eh_timed_out = megasas_reset_timer,

	.shost_attrs = megaraid_host_attrs,

	.bios_param = megasas_bios_param,

	.map_queues = megasas_map_queues,

	.change_queue_depth = scsi_change_queue_depth,

	.max_segment_size = 0xffffffff,

};
@@ -6808,6 +6827,26 @@ static int megasas_io_attach(struct megasas_instance *instance) 
	host->max_lun = MEGASAS_MAX_LUN;

	host->max_cmd_len = 16;



	/* Use shared host tagset only for fusion adaptors

	 * if there are managed interrupts (smp affinity enabled case).

	 * Single msix_vectors in kdump, so shared host tag is also disabled.

	 */



	host->host_tagset = 0;

	host->nr_hw_queues = 1;



	if ((instance->adapter_type != MFI_SERIES) &&

		(instance->msix_vectors > instance->low_latency_index_start) &&

		host_tagset_enable &&

		instance->smp_affinity_enable) {

		host->host_tagset = 1;

		host->nr_hw_queues = instance->msix_vectors -

			instance->low_latency_index_start;

	}



	dev_info(&instance->pdev->dev,

		"Max firmware commands: %d shared with nr_hw_queues = %d\n",

		instance->max_fw_cmds, host->nr_hw_queues);

	/*

	 * Notify the mid-layer about the new controller

	 */

drivers/scsi/megaraid/megaraid_sas_fusion.c

+16 −13
Original line number Diff line number Diff line
@@ -359,25 +359,30 @@ megasas_get_msix_index(struct megasas_instance *instance, 
{

	int sdev_busy;



	/* nr_hw_queue = 1 for MegaRAID */

	struct blk_mq_hw_ctx *hctx =

		scmd->device->request_queue->queue_hw_ctx[0];



	sdev_busy = atomic_read(&hctx->nr_active);

	/* TBD - if sml remove device_busy in future, driver

	 * should track counter in internal structure.

	 */

	sdev_busy = atomic_read(&scmd->device->device_busy);



	if (instance->perf_mode == MR_BALANCED_PERF_MODE &&

	    sdev_busy > (data_arms * MR_DEVICE_HIGH_IOPS_DEPTH))

	    sdev_busy > (data_arms * MR_DEVICE_HIGH_IOPS_DEPTH)) {

		cmd->request_desc->SCSIIO.MSIxIndex =

			mega_mod64((atomic64_add_return(1, &instance->high_iops_outstanding) /

					MR_HIGH_IOPS_BATCH_COUNT), instance->low_latency_index_start);

	else if (instance->msix_load_balance)

	} else if (instance->msix_load_balance) {

		cmd->request_desc->SCSIIO.MSIxIndex =

			(mega_mod64(atomic64_add_return(1, &instance->total_io_count),

				instance->msix_vectors));

	else

	} else if (instance->host->nr_hw_queues > 1) {

		u32 tag = blk_mq_unique_tag(scmd->request);



		cmd->request_desc->SCSIIO.MSIxIndex = blk_mq_unique_tag_to_hwq(tag) +

			instance->low_latency_index_start;

	} else {

		cmd->request_desc->SCSIIO.MSIxIndex =

			instance->reply_map[raw_smp_processor_id()];

	}

}



/**

 * megasas_free_cmds_fusion -	Free all the cmds in the free cmd pool
@@ -956,9 +961,6 @@ megasas_alloc_cmds_fusion(struct megasas_instance *instance) 
	if (megasas_alloc_cmdlist_fusion(instance))

		goto fail_exit;



	dev_info(&instance->pdev->dev, "Configured max firmware commands: %d\n",

		 instance->max_fw_cmds);



	/* The first 256 bytes (SMID 0) is not used. Don't add to the cmd list */

	io_req_base = fusion->io_request_frames + MEGA_MPI2_RAID_DEFAULT_IO_FRAME_SIZE;

	io_req_base_phys = fusion->io_request_frames_phys + MEGA_MPI2_RAID_DEFAULT_IO_FRAME_SIZE;
@@ -1102,8 +1104,9 @@ megasas_ioc_init_fusion(struct megasas_instance *instance) 
		MR_HIGH_IOPS_QUEUE_COUNT) && cur_intr_coalescing)

		instance->perf_mode = MR_BALANCED_PERF_MODE;



	dev_info(&instance->pdev->dev, "Performance mode :%s\n",

		MEGASAS_PERF_MODE_2STR(instance->perf_mode));

	dev_info(&instance->pdev->dev, "Performance mode :%s (latency index = %d)\n",

		MEGASAS_PERF_MODE_2STR(instance->perf_mode),

		instance->low_latency_index_start);



	instance->fw_sync_cache_support = (scratch_pad_1 &

		MR_CAN_HANDLE_SYNC_CACHE_OFFSET) ? 1 : 0;

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