Re: test-pthread-rwlock failure on Pop!_OS 22.04 LTS

[Bruno Haible]

Hi Paul,

These measurements:

> * in virtual machines with 8 CPUs:
> 
>   - Ubuntu 22.04                60 sec      (4 CPUs: 15 sec)
> 
> * outside VirtualBox:
> 
>   - Ubuntu 22.04 (12 CPUs)       6 sec

together with the investigation of the pthread_cond_timedwait "bug",
makes it sound possible that a hypervisor is exercising some influence.

I would therefore be interested in the result of the following
experiment:
  1. Install a toolchain for creating binaries linked against musl-libc:
     $ sudo apt install musl-gcc
  2. Create a testdir for the module 'pthread-rwlock'.
  3. Build it with CC="gcc". You should still see the test failure after
     10 minutes.
  4. Build it with CC="musl-gcc". Run
     $ time gltests/test-pthread-rwlock

If 4. takes more than 30 seconds, your OS is probably running on top of
a hypervisor, and that is causing the problem.

If 4. takes just a few seconds, it looks like a glibc bug.

Bruno