Re: [RFC PATCH 1/2] rcu: Add rcu_read_lock_notrace()
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2025-07-17 15:55:17
Also in:
bpf, linux-rt-devel, rcu
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2025-07-17 15:55:17
Also in:
bpf, linux-rt-devel, rcu
On Thu, 17 Jul 2025 11:40:28 -0400 Steven Rostedt [off-list ref] wrote:
Yes, it is a tracepoint infra problem that we are trying to solve. The reason we are trying to solve it is because BPF programs can extend the time a tracepoint takes. If anything else extended the time, this would need to be solved as well. But currently it's only BPF programs that cause the issue.
BTW, if we can't solve this issue and something else came along and attached to tracepoints that caused unbounded latency, I would also argue that whatever came along would need to be prevented from being configured with PREEMPT_RT. My comment wasn't a strike against BPF programs; It was a strike against something adding unbounded latency into a critical section that has preemption disabled. -- Steve