From 9f0346dcbea363787186c94ef94dd01aaa215afa Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 5 Sep 2026 11:59:05 -0700 Subject: Merge tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core Pull driver core fixes from Danilo Krummrich: - Fix kernfs listxattr() not returning security xattr names (e.g. SELinux labels) when the kernfs node has no allocated kernfs_iattrs - Fix silent truncation of IRQ vector indices in the Rust PCI abstractions - Don't select OF from DRIVER_PE_KUNIT_TEST; skip the test when OF is disabled instead of silently enabling extra kernel functionality - Russ Weight is retiring from kernel development; update the Firmware Loader sysfs contact to the driver-core mailing list, add a CREDITS entry for Firmware Upload, and update MAINTAINERS accordingly * tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: MAINTAINERS: Remove Russ Weight from Firmware Loader CREDITS: Add CREDITS entry for Firmware Upload firmware_loader: Change contact for sysfs nodes rust: pci: reject IRQ vector indices that do not fit in u32 kernfs: preserve security xattrs without allocating iattrs drivers: base: test: DRIVER_PE_KUNIT_TEST should not select OF --- Documentation/networking/dctcp.rst | 52 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 Documentation/networking/dctcp.rst (limited to 'Documentation/networking/dctcp.rst') diff --git a/Documentation/networking/dctcp.rst b/Documentation/networking/dctcp.rst new file mode 100644 index 000000000..4cc8bb2da --- /dev/null +++ b/Documentation/networking/dctcp.rst @@ -0,0 +1,52 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====================== +DCTCP (DataCenter TCP) +====================== + +DCTCP is an enhancement to the TCP congestion control algorithm for data +center networks and leverages Explicit Congestion Notification (ECN) in +the data center network to provide multi-bit feedback to the end hosts. + +To enable it on end hosts:: + + sysctl -w net.ipv4.tcp_congestion_control=dctcp + sysctl -w net.ipv4.tcp_ecn_fallback=0 (optional) + +All switches in the data center network running DCTCP must support ECN +marking and be configured for marking when reaching defined switch buffer +thresholds. The default ECN marking threshold heuristic for DCTCP on +switches is 20 packets (30KB) at 1Gbps, and 65 packets (~100KB) at 10Gbps, +but might need further careful tweaking. + +For more details, see below documents: + +Paper: + +The algorithm is further described in detail in the following two +SIGCOMM/SIGMETRICS papers: + + i) Mohammad Alizadeh, Albert Greenberg, David A. Maltz, Jitendra Padhye, + Parveen Patel, Balaji Prabhakar, Sudipta Sengupta, and Murari Sridharan: + + "Data Center TCP (DCTCP)", Data Center Networks session" + + Proc. ACM SIGCOMM, New Delhi, 2010. + + http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf + http://www.sigcomm.org/ccr/papers/2010/October/1851275.1851192 + +ii) Mohammad Alizadeh, Adel Javanmard, and Balaji Prabhakar: + + "Analysis of DCTCP: Stability, Convergence, and Fairness" + Proc. ACM SIGMETRICS, San Jose, 2011. + + http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp_analysis-full.pdf + +IETF informational draft: + + http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00 + +DCTCP site: + + http://simula.stanford.edu/~alizade/Site/DCTCP.html -- cgit v1.3.1