| Message ID | 20230827072057.1591929-1-zhouchuyi@bytedance.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add Open-coded process and css iters | expand |
Friendly ping... 在 2023/8/27 15:20, Chuyi Zhou 写道: > In some BPF usage scenarios, it will be useful to iterate the process and > css directly in the BPF program. One of the expected scenarios is > customizable OOM victim selection via BPF[1]. > > Inspired by Dave's task_vma iter[2], this patchset adds three types of > open-coded iterator kfuncs: > > 1. bpf_for_each(process, p). Just like for_each_process(p) in kernel to > itearing all tasks in the system with rcu_read_lock(). > > 2. bpf_for_each(css_task, task, css). It works like > css_task_iter_{start, next, end} and would be used to iterating > tasks/threads under a css. > > 3. bpf_for_each(css, pos, root_css, {PRE, POST}). It works like > css_next_descendant_{pre, post} to iterating all descendant css. > > BPF programs can use these kfuncs directly or through bpf_for_each macro. > > link[1]: https://lore.kernel.org/lkml/20230810081319.65668-1-zhouchuyi@bytedance.com/ > link[2]: https://lore.kernel.org/all/20230810183513.684836-1-davemarchevsky@fb.com/ > > Chuyi Zhou (4): > bpf: Introduce css_task open-coded iterator kfuncs > bpf: Introduce process open coded iterator kfuncs > bpf: Introduce css_descendant open-coded iterator kfuncs > selftests/bpf: Add tests for open-coded task and css iter > > include/uapi/linux/bpf.h | 13 ++ > kernel/bpf/helpers.c | 9 ++ > kernel/bpf/task_iter.c | 109 ++++++++++++++++ > tools/include/uapi/linux/bpf.h | 13 ++ > tools/lib/bpf/bpf_helpers.h | 18 +++ > .../testing/selftests/bpf/prog_tests/iters.c | 123 ++++++++++++++++++ > .../testing/selftests/bpf/progs/iters_task.c | 83 ++++++++++++ > 7 files changed, 368 insertions(+) > create mode 100644 tools/testing/selftests/bpf/progs/iters_task.c >
In some BPF usage scenarios, it will be useful to iterate the process and css directly in the BPF program. One of the expected scenarios is customizable OOM victim selection via BPF[1]. Inspired by Dave's task_vma iter[2], this patchset adds three types of open-coded iterator kfuncs: 1. bpf_for_each(process, p). Just like for_each_process(p) in kernel to itearing all tasks in the system with rcu_read_lock(). 2. bpf_for_each(css_task, task, css). It works like css_task_iter_{start, next, end} and would be used to iterating tasks/threads under a css. 3. bpf_for_each(css, pos, root_css, {PRE, POST}). It works like css_next_descendant_{pre, post} to iterating all descendant css. BPF programs can use these kfuncs directly or through bpf_for_each macro. link[1]: https://lore.kernel.org/lkml/20230810081319.65668-1-zhouchuyi@bytedance.com/ link[2]: https://lore.kernel.org/all/20230810183513.684836-1-davemarchevsky@fb.com/ Chuyi Zhou (4): bpf: Introduce css_task open-coded iterator kfuncs bpf: Introduce process open coded iterator kfuncs bpf: Introduce css_descendant open-coded iterator kfuncs selftests/bpf: Add tests for open-coded task and css iter include/uapi/linux/bpf.h | 13 ++ kernel/bpf/helpers.c | 9 ++ kernel/bpf/task_iter.c | 109 ++++++++++++++++ tools/include/uapi/linux/bpf.h | 13 ++ tools/lib/bpf/bpf_helpers.h | 18 +++ .../testing/selftests/bpf/prog_tests/iters.c | 123 ++++++++++++++++++ .../testing/selftests/bpf/progs/iters_task.c | 83 ++++++++++++ 7 files changed, 368 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/iters_task.c