676b7ec67d
Enable HW descriptor prefetch by default by setting plat->dma_cfg->dche = true in intel_mgbe_common_data(). Need to be noted that this capability only be supported in DWMAC core version 5.20 onwards. In stmmac, there is a checking to check the core version. If the core version is below 5.20, this capability wouldn`t be configured. Below is the iperf result comparison between HW descriptor prefetch disabled(DCHE=0b) and enabled(DCHE=1b). Tested on Intel Elkhartlake platform with DWMAC Core 5.20. Observed line rate performance improvement with HW descriptor prefetch enabled. DCHE = 0b [ 5] local 169.254.1.162 port 42123 connected to 169.254.244.142 port 5201 [ ID] Interval Transfer Bitrate Total Datagrams [ 5] 0.00-1.00 sec 96.7 MBytes 811 Mbits/sec 70050 [ 5] 1.00-2.00 sec 96.5 MBytes 809 Mbits/sec 69850 [ 5] 2.00-3.00 sec 96.3 MBytes 808 Mbits/sec 69720 [ 5] 3.00-4.00 sec 95.9 MBytes 804 Mbits/sec 69450 [ 5] 4.00-5.00 sec 96.0 MBytes 806 Mbits/sec 69530 [ 5] 5.00-6.00 sec 96.8 MBytes 812 Mbits/sec 70080 [ 5] 6.00-7.00 sec 96.9 MBytes 813 Mbits/sec 70140 [ 5] 7.00-8.00 sec 96.8 MBytes 812 Mbits/sec 70080 [ 5] 8.00-9.00 sec 97.0 MBytes 814 Mbits/sec 70230 [ 5] 9.00-10.00 sec 96.9 MBytes 813 Mbits/sec 70170 - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Jitter Lost/Total Datagrams [ 5] 0.00-10.00 sec 966 MBytes 810 Mbits/sec 0.000 ms 0/699300 (0%) sender [ 5] 0.00-10.00 sec 966 MBytes 810 Mbits/sec 0.011 ms 0/699265 (0%) receiver DCHE = 1b [ 5] local 169.254.1.162 port 49740 connected to 169.254.244.142 port 5201 [ ID] Interval Transfer Bitrate Total Datagrams [ 5] 0.00-1.00 sec 97.9 MBytes 821 Mbits/sec 70880 [ 5] 1.00-2.00 sec 98.1 MBytes 823 Mbits/sec 71060 [ 5] 2.00-3.00 sec 98.2 MBytes 824 Mbits/sec 71140 [ 5] 3.00-4.00 sec 98.2 MBytes 824 Mbits/sec 71090 [ 5] 4.00-5.00 sec 98.1 MBytes 823 Mbits/sec 71050 [ 5] 5.00-6.00 sec 98.1 MBytes 823 Mbits/sec 71040 [ 5] 6.00-7.00 sec 98.1 MBytes 823 Mbits/sec 71050 [ 5] 7.00-8.00 sec 98.2 MBytes 824 Mbits/sec 71140 [ 5] 8.00-9.00 sec 98.2 MBytes 824 Mbits/sec 71120 [ 5] 9.00-10.00 sec 98.3 MBytes 824 Mbits/sec 71150 - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Jitter Lost/Total Datagrams [ 5] 0.00-10.00 sec 981 MBytes 823 Mbits/sec 0.000 ms 0/710720 (0%) sender [ 5] 0.00-10.00 sec 981 MBytes 823 Mbits/sec 0.041 ms 0/710650 (0%) receiver Signed-off-by: Mohammad Athari Bin Ismail <mohammad.athari.ismail@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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.