On Thu, Jan 2, 2020 at 11:21 PM Bart Van Assche [off-list ref] wrote:

On 12/30/19 2:29 AM, Jack Wang wrote:

quoted

diff --git a/Documentation/ABI/testing/sysfs-class-rtrs-client b/Documentation/ABI/testing/sysfs-class-rtrs-client
new file mode 100644
index 000000000000..8b219cf6c5c4
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-rtrs-client

@@ -0,0 +1,190 @@
+What:                /sys/class/rtrs-client
+Date:                Jan 2020
+KernelVersion:       5.6
+Contact:     Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:
+When a user of RTRS API creates a new session, a directory entry with
+the name of that session is created under /sys/class/rtrs-client/<session-name>/

Thank you for having included this ABI description. This is very
helpful. Please follow the format documented in Documentation/ABI/README
and make sure that all text, including the description, start in column
17 and please use tabs for indentation.

will fix.

quoted

diff --git a/drivers/infiniband/ulp/rtrs/README b/drivers/infiniband/ulp/rtrs/README
new file mode 100644
index 000000000000..59ad60318a18
--- /dev/null
+++ b/drivers/infiniband/ulp/rtrs/README

@@ -0,0 +1,149 @@
+****************************
+InfiniBand Transport (RTRS)
+****************************
+
+RTRS (InfiniBand Transport) is a reliable high speed transport library
+which provides support to establish optimal number of connections
+between client and server machines using RDMA (InfiniBand, RoCE, iWarp)
+transport. It is optimized to transfer (read/write) IO blocks.

Is it explained somewhere how the optimal number of connections is
determined and also according to which metric the number of connections
is optimized? Is the number of connections chosen to minimize latency,
maximize IOPS or perhaps to optimize yet another metric?

RTRS creates one connection per CPU, optimize for minimizing latency
and maximizing IOPS, I would say.

Thanks,

Bart.

Thanks Bart.