2563e2f30a
If possibe, avoid doing a UMR operation to register data and protection buffers (via MTT/KLM mkeys). Instead, use the local DMA key and map the SG lists using PA access. This is safe, since the internal key for data and protection never exposed to the remote server (only signature key might be exposed). If PA mappings are not possible, perform mapping using MTT/KLM descriptors. The setup of the tested benchmark (using iSER ULP): - 2 servers with 24 cores (1 initiator and 1 target) - ConnectX-4/ConnectX-5 adapters - 24 target sessions with 1 LUN each - ramdisk backstore - PI active Performance results running fio (24 jobs, 128 iodepth) using write_generate=1 and read_verify=1 (w/w.o patch): bs IOPS(read) IOPS(write) ---- ---------- ---------- 512 1266.4K/1262.4K 1720.1K/1732.1K 4k 793139/570902 1129.6K/773982 32k 72660/72086 97229/96164 Using write_generate=0 and read_verify=0 (w/w.o patch): bs IOPS(read) IOPS(write) ---- ---------- ---------- 512 1590.2K/1600.1K 1828.2K/1830.3K 4k 1078.1K/937272 1142.1K/815304 32k 77012/77369 98125/97435 Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Israel Rukshin <israelr@mellanox.com> Suggested-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.