scsi: add use_cmd_list flag
Add a use_cmd_list flag in struct Scsi_Host to request keeping track of
all outstanding commands per device.
Default behaviour is not to keep track of cmd_list per sdev, as this may
introduce lock contention. (overhead is more on multi-node NUMA.), and
only enable it on the two drivers that need it.
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index ba20347..cafb260 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -680,6 +680,7 @@
unsigned no_write_same:1;
unsigned use_blk_mq:1;
+ unsigned use_cmd_list:1;
/*
* Optional work queue to be utilized by the transport