It turns out there is still a small race which can make the arena free list cyclic.
This bug is due to an incorrect fix for bug 1281714.
This bug appears to have been reported against 'rawhide' during the Fedora 25 development cycle. Changing version to '25'.
The upstream branches for 2.23, 2.24 and master now contain this fix.
2.22 as well.
glibc-2.24-3.fc25 has been submitted as an update to Fedora 25. https://bodhi.fedoraproject.org/updates/FEDORA-2016-57cba655d5
glibc-2.23.1-10.fc24 has been submitted as an update to Fedora 24. https://bodhi.fedoraproject.org/updates/FEDORA-2016-5f050a0a6d
glibc-2.24-3.fc25 has been pushed to the Fedora 25 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2016-57cba655d5
glibc-2.23.1-10.fc24 has been pushed to the Fedora 24 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2016-5f050a0a6d
glibc-2.23.1-10.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.
glibc-2.24-3.fc25 has been pushed to the Fedora 25 stable repository. If problems still persist, please make note of it in this bug report.