PRs already reviewed

Emantor · March 29, 2020, 3:33pm

I cross checked debian and arch, should be good to merge:

github.com/NixOS/nixpkgs

linux config: Set TCP_CONG_CUBIC=yes to restore the default

NixOS:staging ← primeos:tcp-cong-switch-to-cubic

opened 10:00AM - 02 Mar 20 UTC

primeos

+1 -0

This will switch the default TCP congestion control algorithm from new Reno to …CUBIC. CUBIC is the default since Linux kernel 2.6.19 (see 597811ec167fa) and most (all?) distributions keep this default (e.g. Debian and Ubuntu). On NixOS the default was still new Reno because generate-config.pl changes TCP_CONG_CUBIC from y to m (since we try to build everything as a module by default). To check the active and available algorithms: $ sysctl net.ipv4.tcp_congestion_control net.ipv4.tcp_congestion_control = cubic $ sysctl net.ipv4.tcp_available_congestion_control net.ipv4.tcp_available_congestion_control = cubic reno Note: E.g. x86_64_defconfig sets TCP_CONG_CUBIC=y indirectly via CONFIG_TCP_CONG_ADVANCED=y (but CUBIC is also the default if set to no, see net/ipv4/Kconfig). ``` Edit: Some existing diffs (old NixOS kernel configuration vs. other distributions): - Ubuntu: https://github.com/NixOS/nixpkgs/issues/58275#issuecomment-477203331 - Arch: https://github.com/NixOS/nixpkgs/issues/39225#issuecomment-385281048 ``` ###### Motivation for this change ###### Things done - [ ] Tested using sandboxing ([nix.useSandbox](http://nixos.org/nixos/manual/options.html#opt-nix.useSandbox) on NixOS, or option `sandbox` in [`nix.conf`](http://nixos.org/nix/manual/#sec-conf-file) on non-NixOS linux) - Built on platform(s) - [ ] NixOS - [ ] macOS - [ ] other Linux distributions - [ ] Tested via one or more NixOS test(s) if existing and applicable for the change (look inside [nixos/tests](https://github.com/NixOS/nixpkgs/blob/master/nixos/tests)) - [ ] Tested compilation of all pkgs that depend on this change using `nix-shell -p nixpkgs-review --run "nixpkgs-review wip"` - [ ] Tested execution of all binary files (usually in `./result/bin/`) - [ ] Determined the impact on package closure size (by running `nix path-info -S` before and after) - [ ] Ensured that relevant documentation is up to date - [ ] Fits [CONTRIBUTING.md](https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md).