Hi, On 1/10/2025 6:21 AM, Chris Friesen wrote: > Hi, > > Back in 2019 there were some concerns raised > (https://lwn.net/ml/bpf/20191017090500.ienqyium2phkxpdo@xxxxxxxxxxxxx/#t) > around using BPF in conjunction with PREEMPT_RT. > > In the context of the 6.6 kernel and the corresponding PREEMPT_RT > patchset, are those concerns still valid or have they been sorted out? > > Please CC me on replies, I'm not subscribed to the list. Do you have any use case for BPF + PREEMPT_RT ? I am not a RT expert, however, In my understanding, BPF + PREEMPT_RT in the vanilla kernel basically can work togerther basically. The memory allocation concern is partially resolved and there is still undergoing effort trying to resolve it [1]. The up_read_non_owner problem has been avoided explicitly and the non-preemptible context for bpf prog has also been fixed. Although the running of test_maps and test_progs under PREEMPT_RT report some problems, I think these problem could be fixed. As for v6.6, I think it may be OK for BPF + PREEMPT_RT case. [1]: https://lore.kernel.org/bpf/20241210023936.46871-1-alexei.starovoitov@xxxxxxxxx/ > Thanks, > Chris Friesen > > > .
