Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 18 Mar 2024 08:54:39 -0700 | Subject | Re: [PATCH V2 bpf-next 1/2] bpf: add bpf_task_get_cgroup kfunc | From | Yonghong Song <> |
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On 3/16/24 9:22 AM, Jose Fernandez wrote: > This patch enhances the BPF helpers by adding a kfunc to retrieve the > cgroup v2 of a task, addressing a previous limitation where only > bpf_task_get_cgroup1 was available for cgroup v1. The new kfunc is > particularly useful for scenarios where obtaining the cgroup ID of a > task other than the "current" one is necessary, which the existing > bpf_get_current_cgroup_id helper cannot accommodate. A specific use > case at Netflix involved the sched_switch tracepoint, where we had to > get the cgroup IDs of both the prev and next tasks. > > The bpf_task_get_cgroup kfunc acquires and returns a reference to a > task's default cgroup, ensuring thread-safe access by correctly > implementing RCU read locking and unlocking. It leverages the existing > cgroup.h helper, and cgroup_tryget to safely acquire a reference to it. > > Signed-off-by: Jose Fernandez <josef@netflix.com> > Reviewed-by: Tycho Andersen <tycho@tycho.pizza>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
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