On Wed, 12 Nov 2025 13:27:10 +0800 Yongliang Gao <[email protected]> wrote:
> Thank you for your detailed response and the proposed RCU-like approach. > > I've looked into using a regular seqlock instead of the current > implementation, but as you pointed out, the write side is indeed a > critical path. More importantly, I found that even with seqlock, the > write_seqlock() function internally uses spin_lock() which on > PREEMPT_RT gets converted to an mutex. This would cause the same > issues we're trying to avoid - potential sleep in atomic contexts. I believe there is a raw_read_seqcount() functionality that is safe for PREEMPT_RT. Have you looked into using that? -- Steve
