Internal On Fri, 30 Oct 2026 10:54:11 +0000 =?utf-8?B?VG9iaWFzIFNjaMO8bGVpbg==?= <[email protected]> wrote: > On Fri, 30 Oct 2026 08:35:55 +0100 Aurelien Jarno <[email protected]> wrote:
> > Do you mind providing a bit more details on how you found this bug and > > what are the consequences, it might also help to decide if this bug > > needs to be fixed in trixie or not, as it is technically not a > > regression from bookworm or even bullseye. > > The bug was found by unit tests bound to a mutex wrapper layer in our code > base. > As this wrapper is totally under our control, it’s easy for us to apply a > workaround in a central place: > - Replace the affected pthread_mutex_trylock() call with e.g. > pthread_mutex_clocklock() waiting on an already expired timeout. > > So after all, from my pov, we are good with the workaround and happy when a > proper fix appears per upstream path for the next Debian major version. Unfortunately, we found out that the workaround “use pthread_mutex_clocklock() on an already expired timeout” has drawbacks in an RT environment when working with PI-safe mutexes (PTHREAD_PRIO_INHERIT): The kernel sometimes reverts a PI boosted task to its original priority too late causing latency issues for high priority task. We see this at least on our 6.12.17 PREEMPT_RT based kernel. So this workaround is not viable for the production platform and means that we are interested in a backport to Trixie for the glibc issue in BZ#27458. Thanks, Tobias Mit freundlichen Grüßen / Kind regards i. A. Tobias Schülein Team Leader OS RT System R&D ASF KUKA Deutschland GmbH Zugspitzstraße 140, 86165 Augsburg / Germany www.kuka.com<http://www.kuka.com/> [email protected]<mailto:[email protected]> T +49 821 797‑3925 KUKA Deutschland GmbH Board of Directors: Michael Jürgens (Chairman), Johan Naten, Hui Zhang Registered Office: Augsburg HRB 14914 This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorized copying, disclosure or distribution of contents of this e-mail is strictly forbidden. Please consider the environment before printing this e-mail.
