| 20 Jul 2024 |
 Traxys | Yeah | 20:51:47 |
 Mic92 | Sounds like something that would actually make parallel evaluation slower | 20:51:50 |
| Traxys | I'd say it had about 300 derivations? | 20:52:12 |
| Traxys | (as a 1000 checks were with all 4 architectures) | 20:52:54 |
| Traxys | We had a link farm I think mostly for the reason fixed by https://github.com/nix-community/buildbot-nix/pull/217
Though I have a question, why does using a link farm consume more RAM than splitting them up? Shouldn't we expect the same result in-fine ? | 20:56:38 |
 magic_rb | Iirc nix doesnt really do GC that well | 20:59:08 |
| magic_rb | So it doesnt GC as much as you would think it should | 20:59:23 |
 aidalgol | Do you mean the nix store, or nix the language and runtime? | 21:38:51 |
| aidalgol | * Do you mean the nix store, or the nix language runtime? | 21:40:34 |
 tomberek | The language GC (to help control memory usage) is quite costly. It is also very conservative, so it is not as beneficial as it might be if we had a dedication allocation and GC system that understood Nix semantics. With additional strictness or linearity analysis it is possible we could collect many more values. Nixpkgs is also a big to blame here, it is built in a way that makes it harder to GC things. | 21:41:35 |
| tomberek | * The language GC (to help control memory usage) is quite costly. It is also very conservative, so it is not as beneficial as it might be if we had a dedication allocation and GC system that understood Nix semantics. With additional strictness or linearity analysis it is possible we could collect many more values. Nixpkgs is also a bit to blame here, it is built in a way that makes it harder to GC things. | 21:41:49 |
 zowoq | In reply to @traxys:familleboyer.net
zowoq I tried running the command you provided with this PR and I get a Maximum Resident Set Size of 4.7 GiB, is this more acceptable? Yes, that will fix it. | 23:42:44 |
| 21 Jul 2024 |
| magic_rb | In reply to @tomberek:matrix.org
The language GC (to help control memory usage) is quite costly. It is also very conservative, so it is not as beneficial as it might be if we had a dedication allocation and GC system that understood Nix semantics. With additional strictness or linearity analysis it is possible we could collect many more values. Nixpkgs is also a big to blame here, it is built in a way that makes it harder to GC things. How does nixpkgs contribute to the problem? | 08:01:54 |
 emily | everything is circular | 08:16:41 |
 @aloisw:kde.org | In reply to @magic_rb:matrix.redalder.org
How does nixpkgs contribute to the problem? Nixpkgs derivations remember too much of their inputs. | 08:29:44 |
| Traxys | zowoq we merged the PR that reduced the memory usage. We'd need to ask all open PRs to rebase on main, and we should be good to re-enable buildbot | 13:22:20 |
 Matt Sturgeon | Was our stable branch affected by the issue?
Do we need to disable buildbot on that branch until the change is backported, or since it is a low traffic branch is it enough that we simply avoid triggering any CI builds on stable for now? | 13:39:16 |
| Traxys | I don't really know :/ | 14:00:57 |
| Matt Sturgeon | I'm out and about so can't check right now, but we can try running the eval command on our stable branch to see?
nix run nixpkgs#nix-eval-jobs -- --workers 1 --check-cache-status --force-recurse --flake 'github:nix-community/nixvim/nixos-24.05#checks'
Or just enable buildbot and test it on the branch when someone's around to restart it if it crashes? | 14:44:58 |
| zowoq | I think you'll need https://github.com/nix-community/buildbot-nix/pull/217 as well to avoid the rate limit problems https://github.com/nix-community/buildbot-nix/issues/178? | 22:24:25 |
| 22 Jul 2024 |
| Traxys | When I launched a job I did not encounter that, but that may be because it was a single job, and if we switched on buildbot we would have issues due with many PRs | 08:11:48 |
| Traxys | (and I think our stable branch is affected too, so we need to backport some of this) | 08:12:07 |
 Clumsily6239 | Can I login into a user without triggering their ~/.config/autostart and systemd user services? | 12:38:36 |
 K900 | Depends on your definition of "login" | 12:38:58 |
| Clumsily6239 | the standard login from tty? I thought that was the only "login". | 12:40:09 |
| K900 | Log in as root, sudo -u <your user> | 12:40:39 |
| K900 | e.g. | 12:40:43 |
| Clumsily6239 | Awesome, thank you. | 12:41:35 |
| 23 Jul 2024 |
| zowoq | https://docs.github.com/en/apps/oauth-apps/building-oauth-apps/differences-between-github-apps-and-oauth-apps
The rate limit for GitHub Apps using an installation access token scales with the number of repositories and number of organization users. Conversely, OAuth apps have lower rate limits and do not scale.
Maybe the size of nix-community means the rate limits aren't a problem.
| 01:05:52 |
| zowoq | I checked stable and it seems to use a lot less memory than it was on main so I've enabled buildbot again. | 01:06:07 |
