| 11 Oct 2024 |
 jakehamilton | In reply to @k900:0upti.me
nix-eval-jobs is not multithreaded inside a single eval I see, that tracks with what my gut was telling me. Thank you for the clarification! | 14:55:50 |
 Tristan Ross | I've benchmarked the multithreaded evaluator quite a bit between single core and 64 cores, at some point, the performance degrades because it seems there's just not enough jobs available for the limit. | 15:04:32 |
| Tristan Ross | It's kinda interesting because with a nix flake check, it seems to depend on the number of attributes on the outputs attr set | 15:05:18 |
 aloisw | Don't they only evaluate different outputs in parallel? | 16:04:17 |
 KFears (tragedy arc) | In reply to @k900:0upti.me
Generally I don't think it's really a good solution because we don't even know what the bottlenecks are most of the time Really handy that OTLP is interested in merging profiling:
https://github.com/open-telemetry/oteps/blob/main/text/profiles/0239-profiles-data-model.md | 16:14:10 |
| KFears (tragedy arc) | https://github.com/open-telemetry/opentelemetry-cpp/issues/2657 | 16:19:19 |
 K900 | Yeah probably won't help us much, the real problem is mapping evaluator spans back to Nix code | 16:20:39 |
| KFears (tragedy arc) | Grafana Pyroscope has profiles-to-traces, which can help a bit | 16:23:00 |
| KFears (tragedy arc) | But it's a hard problem with solutions that didn't even hit bleeding edge yet, for sure | 16:23:27 |
| KFears (tragedy arc) | I wonder if it's possible to get NixLang to support OTLP tracing. Would be possible to track spans across Nix/C++ boundary... | 16:29:40 |
| 12 Oct 2024 |
|  Kevin Tran joined the room. | 00:11:47 |
| Kevin Tran | Download 8nmaa2n1msjbik2cdwdknmyz26jk2iwl-lix-2.91.0.txt | 00:13:44 |
| Kevin Tran | i was update my flake.lock and rebuilding with darwin-rebuild, when i got this error message. i am running macos sequoia | 00:13:59 |
|  Federico Damián Schonborn changed their profile picture. | 00:30:56 |
| Tristan Ross | In reply to @aloisw:kde.org
Don't they only evaluate different outputs in parallel? Yeah, each output takes a job which I think is where this sort of causes the performance degradation after a certain number of cores being made available. | 02:05:15 |
 julia | I mean also my understanding is the implementation was just mutexes everywhere... (... a custom implementation for the quoted reason of not wanting to use mutexes, except they reimplemented the whole worker thread waiting but in userspace) | 02:44:15 |
| julia | * I mean also my understanding is the implementation was just mutexes everywhere... (... a custom implementation for the quoted reason of not wanting to use mutexes, except they reimplemented the whole worker thread waiting but in userspace and used CAS i.e. mutex) | 02:45:22 |
| K900 | It's a new, uniquely cursed form of synchronization primitive | 06:34:05 |
| K900 | An eetex | 06:34:08 |
| aloisw | Custom mutex implemented using mutexes, to be precise. | 07:56:02 |
|  @eida:techniverse.net joined the room. | 08:46:08 |
| @eida:techniverse.net left the room. | 08:51:28 |
 uep | why has noone invented the µtex | 10:09:41 |
 antifuchs | In reply to @k900:0upti.me
An eetex The small, less threatening variant would be the moo-dengtex? | 12:04:08 |
| KFears (tragedy arc) | DetSystex | 12:23:02 |
 qbit | trying to get my darwin-aarch64 machine over the nix->lix bump | 14:08:27 |
| qbit | oh hrm: nix (Nix) 2.18.4 | 14:08:54 |
| qbit | oh, maybe my machine isn’t using the module.. | 14:09:41 |
| qbit | k, added it to the modules, but when I try to do darwin-rebuild switch —flake github:qbit/xin —refresh i get:
building the system configuration...
error:
… while setting up the build environment
error: getting attributes of path '/private/tmp/nix-build-builder.pl.drv-0/build: Permission denied
| 14:15:58 |
| qbit | guess i’ll try as root :P | 14:16:23 |
