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| author | Dapeng Mi <dapeng1.mi@linux.intel.com> | 2026-09-17 09:52:33 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2026-09-22 11:37:46 +0200 |
| commit | 0102c8c7fdfc4bd700971daff2b94470f4eafae4 (patch) | |
| tree | 531306c2299f9a269f0a986e29f17ba972180104 /Documentation/networking/dctcp.rst | |
| download | linux-stable-0102c8c7fdfc4bd700971daff2b94470f4eafae4.tar.gz linux-stable-0102c8c7fdfc4bd700971daff2b94470f4eafae4.zip | |
perf/x86/intel: Rename DMR offcore_rsp attribute to offmodule_rspgrafted
DMR introduces Offmodule Response events in place of the legacy
Offcore Response events, but it still exposes the inherited
offcore_rsp PMU attribute for programming the corresponding MSR data.
Rename the DMR PMU attribute to offmodule_rsp so the sysfs interface
matches the underlying event name and avoids user & tooling confusion.
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20260917015234.981153-12-dapeng1.mi@linux.intel.com
Diffstat (limited to 'Documentation/networking/dctcp.rst')
| -rw-r--r-- | Documentation/networking/dctcp.rst | 52 |
1 files changed, 52 insertions, 0 deletions
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 |