Commit 1ba7c8f8 authored Sep 12, 2019 by Sergey Gorenko Committed by Jason Gunthorpe Sep 13, 2019

IB/iser: Support up to 16MB data transfer in a single command

Maximum supported IO size is 8MB for the iSER driver. The current value is
limited by the ISCSI_ISER_MAX_SG_TABLESIZE macro. But the driver is able
to handle 16MB IOs without any significant changes. Increasing this limit
can be useful for the storage arrays which are fine tuned for IOs larger
than 8 MB.

This commit allows to configure maximum IO size up to 16MB using the
max_sectors module parameter.

Link: https://lore.kernel.org/r/20190912103534.18210-1-sergeygo@mellanox.com


Signed-off-by: Sergey Gorenko <sergeygo@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

parent 0404bd62

drivers/infiniband/ulp/iser/iscsi_iser.h

+4 −3

Original line number	Diff line number	Diff line
		@@ -102,9 +102,10 @@

		/* Default support is 512KB I/O size */
		#define ISER_DEF_MAX_SECTORS 1024
		#define ISCSI_ISER_DEF_SG_TABLESIZE ((ISER_DEF_MAX_SECTORS * 512) >> SHIFT_4K)
		/* Maximum support is 8MB I/O size */
		#define ISCSI_ISER_MAX_SG_TABLESIZE ((16384 * 512) >> SHIFT_4K)
		#define ISCSI_ISER_DEF_SG_TABLESIZE \
		((ISER_DEF_MAX_SECTORS * SECTOR_SIZE) >> SHIFT_4K)
		/* Maximum support is 16MB I/O size */
		#define ISCSI_ISER_MAX_SG_TABLESIZE ((32768 * SECTOR_SIZE) >> SHIFT_4K)

		#define ISER_DEF_XMIT_CMDS_DEFAULT 512
		#if ISCSI_DEF_XMIT_CMDS_MAX > ISER_DEF_XMIT_CMDS_DEFAULT