[PATCH v2 03/12] scsi-mq: Add support for multiple hardware queues

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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

Note: it is assumed that each hardware queue has a queue depth of
shost->can_queue. In other words, the total queue depth per host
is (number of hardware queues) * (shost->can_queue).

Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
---
 drivers/scsi/scsi_lib.c  | 2 +-
 include/scsi/scsi_host.h | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index db8c449..f829c42 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2072,7 +2072,7 @@ 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;
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index cafb260..d38cab9 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -638,6 +638,10 @@ 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.
+	 */
+	unsigned nr_hw_queues;
 	/* 
 	 * Used to assign serial numbers to the cmds.
 	 * Protected by the host lock.
-- 
1.8.4.5

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Linux IIO]     [Samba]     [Device Mapper]
  Powered by Linux