| Summary: | valgrind hangs and is totally unresponsive running a very "simple" Rust program that uses glommio | ||
|---|---|---|---|
| Product: | [Developer tools] valgrind | Reporter: | vlovich |
| Component: | general | Assignee: | Julian Seward <jseward> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | mark, pjfloyd |
| Priority: | NOR | ||
| Version: | 3.19.0 | ||
| Target Milestone: | --- | ||
| Platform: | Arch Linux | ||
| OS: | Linux | ||
| Latest Commit: | Version Fixed In: | ||
| Sentry Crash Report: | |||
| Attachments: | Repro test case | ||
glommio bug tracking this: https://github.com/DataDog/glommio/issues/582 Also what may be relevant about this framework is that each thread has a separate io_uring poll loop and that's how all the IPC socket comms between threads are happening. So I wonder if it's something to do with valgrind / io_uring interop somehow? Also repros on valgrind-git package (valgrind-git-3.20.0.r9.g0811a612d-1) which when run prints Valgrind-3.21.0.GIT See also Bug #439226 Multiple io_urings per thread not supported and Bug #428364 Signals inside io_uring_enter not handled The patch from https://bugs.kde.org/show_bug.cgi?id=428364 seems to also fix this. When I try to reproduce a single ctrl-c is enough to interrupt the process. |
Created attachment 155045 [details] Repro test case SUMMARY I have a very "simple" program that uses the ChannelMesh functionality of glommio. When run under valgrind, the test code STEPS TO REPRODUCE 1. Install rust 2. Decompress the file (it has a nested folder of the same name) 3. cargo build 4. valgrind target/debug/valgrind-deadlock OBSERVED RESULT Valgrind hangs pretty quickly and is totally unresponsive - ctrl-c doesn't work and I have to `pkill -9 -f valgrind`. ``` valgrind --fair-sched=yes target/debug/valgrind-deadlock ==852776== Memcheck, a memory error detector ==852776== Copyright (C) 2002-2022, and GNU GPL'd, by Julian Seward et al. ==852776== Using Valgrind-3.19.0 and LibVEX; rerun with -h for copyright info ==852776== Command: target/debug/valgrind-deadlock ==852776== Started thread 2 Started thread 1 ^C^C^ZKilled ``` EXPECTED RESULT The program completes successfully and valgrind is responsive (i.e. ctrl-c will work). SOFTWARE/OS VERSIONS Linux/KDE Plasma: (available in About System) KDE Plasma Version: 5.26.5 KDE Frameworks Version: 5.101.0 Qt Version: 5.15.7 ADDITIONAL INFORMATION Kernel: 6.0.8-arch1-1 (64-bit) Processors: 12 x Intel i7-10750H CPU @ 2.6 GHz Memory: 31.1 GiB of RAM I've also tried with `--fair-sched=yes` and that has no effect. It looks like a thread is never getting started and thus the main thread is stuck waiting for it to start. We've not been able to find any documentation online that might explain this behavior / what's happening.