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

This reverts commit 103fbf8e4020845e4fcf63819288cedb092a3c91.

It turns out that it causes long boot-time latencies (to the point of
timeouts and failed boots).

The cause is the increase in request queues, and a fix for that is
queued up for 5.11, but we're reverting this commit that triggered the
problem for now.

Reported-and-tested-by: John Garry <john.garry@huawei.com>
Reported-and-tested-by: Julia Lawall <julia.lawall@inria.fr>
Reported-by: Qian Cai <cai@redhat.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/linux-scsi/fe3dff7dae4494e5a88caffbb4d877bbf472dceb.camel@redhat.com/
Link: https://lore.kernel.org/lkml/alpine.DEB.2.22.394.2012081813310.2680@hadrien/
Link: https://lore.kernel.org/linux-block/20201203012638.543321-1-ming.lei@redhat.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 39 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index 41cd66fc7d81..e158d3d62056 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -37,7 +37,6 @@
 #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>
@@ -114,10 +113,6 @@ 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");
@@ -3124,19 +3119,6 @@ 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);
 
 /**
@@ -3445,7 +3427,6 @@ 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,
 };
@@ -6827,26 +6808,6 @@ 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
 	 */