Hi, We are evaluating eBPF as a means to account voluntary and non-voluntary context switches against cgroups. Currently, this information is only present in the task_struct for an individual process and not in the cgroup data structure. With this context, I was looking for recommendation on the following possible approaches: 1. Use the existing tracepoint (trace_sched_switch) as it exists here with BPF_PROG_TYPE_TRACEPOINT: https://github.com/torvalds/linux/blob/master/kernel/sched/core.c#L3877 However, based on the trace format, the kernel does not expose prev->nivcsw and prev->nvcsw. Due to this, I feel like this approach may not be feasible. Is my understanding correct? 2. Attach a kprobe to __schedule() and use BPF_PROG_TYPE_KPROBE This will allow us access to the prev pointer. From the prev (task_struct), we can access the cgroup and use an eBPF map to accumulate per cgroup counts of context switches. 3. Implement a kernel module that attaches a kprobe to __schedule() and implement the map in the kprobe handler. 4. Modify the kernel to have context switch information in task_group. Would this be something that would make sense to the community? I would highly appreciate any feedback on this. Regards, Gautam
