Re: [patch 00/12] futex: Cure robust/PI futex exit races

From: Florian Weimer
Date: Thu Nov 07 2019 - 17:41:00 EST


* Florian Weimer:

> * Thomas Gleixner:
>
>> The series is also available from git:
>>
>> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git WIP.locking/futex
>
> I ran the glibc upstream test suite (which has some robust futex tests)
> against b21be7e942b49168ee15a75cbc49fbfdeb1e6a97 on x86-64, both native
> and 32-bit/i386 compat mode.
>
> compat mode seems broken, nptl/tst-thread-affinity-pthread fails. This
> is probably *not* due to
> <https://bugzilla.kernel.org/show_bug.cgi?id=154011> because the failure
> is non-sporadic, but reliable fails for thread 253:
>
> info: Detected CPU set size (in bits): 225
> info: Maximum test CPU: 255
> error: pthread_create for thread 253 failed: Resource temporarily unavailable
>
> I'm running this on a large box as root, so ulimits etc. do not apply.
>
> I did not see this failure with the x86-64 test.
>
> You should be able to reproduce with (assuming you've got a multilib gcc):
>
> git clone git://sourceware.org/git/glibc.git git
> mkdir build
> cd build
> ../git/configure --prefix=/usr CC="gcc -m32" CXX="g++ -m32" --build=i686-linux
> make -j`nproc`
> make test t=nptl/tst-thread-affinity-pthread

Sorry, I realized that I didn't actually verify that this is a
regression caused by your patches. Maybe I can do that tomorrow.

Florian