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| author |   Honggang Li <honli@redhat.com> | 2019-09-28 01:43:51 +0800 |
|---|---|---|
| committer |   Jason Gunthorpe <jgg@mellanox.com> | 2019-10-08 15:17:32 -0300 |
| commit | 547ed331bbe89575ff91939e1ac9a023fe526b74 (patch) | |
| tree | 601b7c0e9341eb4d2bfdb05f7896336a53c1d393 /Documentation | |
| parent | IB/cm: Use container_of() instead of typecast (diff) | |
| download | linux-dev-547ed331bbe89575ff91939e1ac9a023fe526b74.tar.xz linux-dev-547ed331bbe89575ff91939e1ac9a023fe526b74.zip | |
RDMA/srp: Add parse function for maximum initiator to target IU size
According to SRP specifications 'srp-r16a' and 'srp2r06',
IOControllerProfile attributes for SRP target port include the maximum
initiator to target IU size.
SRP connection daemons, such as srp_daemon, can get the value from the
subnet manager. The SRP connection daemon can pass this value to kernel.
This patch adds a parse function for it.
Upstream commit [1] enables the kernel parameter, 'use_imm_data', by
default. [1] also use (8 * 1024) as the default value for kernel parameter
'max_imm_data'. With those default values, the maximum initiator to target
IU size will be 8260.
In case the SRPT modules, which include the in-tree 'ib_srpt.ko' module,
do not support SRP-2 'immediate data' feature, the default maximum
initiator to target IU size is significantly smaller than 8260. For
'ib_srpt.ko' module, which built from source before [2], the default
maximum initiator to target IU is 2116.
[1] introduces a regression issue for old srp targets with default kernel
parameters, as the connection will be rejected because of a too large
maximum initiator to target IU size.
[1] commit 882981f4a411 ("RDMA/srp: Add support for immediate data")
[2] commit 5dabcd0456d7 ("RDMA/srpt: Add support for immediate data")
Link: https://lore.kernel.org/r/20190927174352.7800-1-honli@redhat.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Honggang Li <honli@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/stable/sysfs-driver-ib_srp | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-driver-ib_srp b/Documentation/ABI/stable/sysfs-driver-ib_srp index 7049a2b50359..84972a57caae 100644 --- a/Documentation/ABI/stable/sysfs-driver-ib_srp +++ b/Documentation/ABI/stable/sysfs-driver-ib_srp @@ -67,6 +67,8 @@ Description: Interface for making ib_srp connect to a new target. initiator is allowed to queue per SCSI host. The default value for this parameter is 62. The lowest supported value is 2. + * max_it_iu_size, a decimal number specifying the maximum + initiator to target information unit length. What: /sys/class/infiniband_srp/srp-<hca>-<port_number>/ibdev Date: January 2, 2006 |