NikoMar 23

hi there rust peeps

does anyone have any clue why a tokio runtime would have a hard cap on the number of tasks at 32,768?

hitting this limit silently fails to spawn new tasks and existing tasks hit "device or resource busy" errors when they need to use IO

no ulimits have been hit as far as i can tell (83 open files, well under limit of 16,384, and all other limits are either unlimited or unrelated to this issue)

given the failure mode is completely silent i have no clue where to start debugging this

Show threadunnick
@niko i asked @iczero about this and he was able to spawn 512k tasks fine apparently. he suggested you might be limited by cgroups and not ulimit
Mar 23 at 11:35amWeb
Show threadNikoMar 23

@unnick @iczero yeah i'm unsurprised at this because i've spawned >100 million tasks before just fine

i'm not quite sure what would be limiting here with cgroups, got any ideas i can chase on this one?

Show threadNikoMar 23
@unnick @iczero the behaviour i observe as well doesn't quite match up to a user-level limit because it's just this process that's limited, anything else running on the whole system continues to function normally