On 2025-04-09 08:41:44 [+0200], Jan Kiszka wrote: > We are hunting for quite some time sporadic lock-ups or RT systems, > first only in the field (sigh), now finally also in the lab. Those have > a fairly high overlap with what was described here. Our baselines so > far: 6.1-rt, Debian and vanilla. We are currently preparing experiments > with latest mainline. > > While this thread remained silent afterwards, we have found [1][2][3] as > apparently related. But this means we are still with this RT bug, even > in latest 6.15-rc1? Not sure the commits are related. The problem here is that RW locks are not really real time friendly. Frederick had a simple fix to it https://lore.kernel.org/all/20210825132754.GA895675@lothringen/ but yeah. The alternative, which I didn't look into, would be to replace the reader side with RCU so we would just have the writer lock. That mean we need to RW lock because of performance… > Jan > > [1] https://lore.kernel.org/lkml/20231030145104.4107573-1-vschneid@xxxxxxxxxx/ > [2] https://lore.kernel.org/lkml/20240202080920.3337862-1-vschneid@xxxxxxxxxx/ > [3] https://lore.kernel.org/lkml/20250220093257.9380-1-kprateek.nayak@xxxxxxx/ > Sebastian
