Commit efec4b90 authored by Bart Van Assche's avatar Bart Van Assche Committed by Christoph Hellwig
Browse files

scsi: add support for multiple hardware queues 



Allow a SCSI LLD to declare how many hardware queues it supports
by setting Scsi_Host.nr_hw_queues before calling scsi_add_host().

Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Reviewed-by: default avatarSagi Grimberg <sagig@mellanox.com>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 205fb5f5

drivers/scsi/scsi_lib.c

+1 −1
Original line number Diff line number Diff line
@@ -2106,7 +2106,7 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost) 


	memset(&shost->tag_set, 0, sizeof(shost->tag_set));

	shost->tag_set.ops = &scsi_mq_ops;

	shost->tag_set.nr_hw_queues = 1;

	shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1;

	shost->tag_set.queue_depth = shost->can_queue;

	shost->tag_set.cmd_size = cmd_size;

	shost->tag_set.numa_node = NUMA_NO_NODE;

include/scsi/scsi_host.h

+8 −0
Original line number Diff line number Diff line
@@ -638,6 +638,14 @@ struct Scsi_Host { 
	short unsigned int sg_prot_tablesize;

	unsigned int max_sectors;

	unsigned long dma_boundary;

	/*

	 * In scsi-mq mode, the number of hardware queues supported by the LLD.

	 *

	 * Note: it is assumed that each hardware queue has a queue depth of

	 * can_queue. In other words, the total queue depth per host

	 * is nr_hw_queues * can_queue.

	 */

	unsigned nr_hw_queues;

	/* 

	 * Used to assign serial numbers to the cmds.

	 * Protected by the host lock.

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