[PATCH bpf-next 0/2] Add new bpf_cpumask_weight() kfunc

David Vernet
2023-12-07T21:09:03Z

It can be useful to query how many bits are set in a cpumask. For
example, if you want to perform special logic for the last remaining
core that's set in a mask. This logic is already exposed through the
main kernel's cpumask header as cpumask_weight(), so it would be useful
to add a new bpf_cpumask_weight() kfunc which wraps it and does the
same.

This patch series was built and tested on top of commit 2146f7fe6e02
("Merge branch 'allocate-bpf-trampoline-on-bpf_prog_pack'").

David Vernet (2):
bpf: Add bpf_cpumask_weight() kfunc
selftests/bpf: Add test for bpf_cpumask_weight() kfunc

Documentation/bpf/cpumasks.rst | 2 +-
kernel/bpf/cpumask.c | 12 ++++++
.../selftests/bpf/prog_tests/cpumask.c | 1 +
.../selftests/bpf/progs/cpumask_common.h | 1 +
.../selftests/bpf/progs/cpumask_success.c | 43 +++++++++++++++++++
5 files changed, 58 insertions(+), 1 deletion(-)

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2.42.1