Changes to bpf.h tend to clog up our build systems. The netdev/bpf build bot does incremental builds to save time (reusing the build directory to only rebuild changed objects). This is the rough breakdown of how many objects needs to be rebuilt based on file touched: kernel.h 40633 bpf.h 17881 bpf-cgroup.h 17875 skbuff.h 10696 bpf-netns.h 7604 netdevice.h 7452 filter.h 5003 tcp.h 4048 sock.h 4959 As the stats show touching bpf.h is _very_ expensive. Recent 20+ patch series from Jirka took 10 hours to build patch-by-patch on a 72 CPU VM. Bulk of the objects get rebuilt because MM includes cgroup headers. Luckily bpf-cgroup.h does not fundamentally depend on bpf.h so we can break that dependency and reduce the number of objects. With the patches applied touching bpf.h causes 5019 objects to be rebuilt (17881 / 5019 = 3.56x). That's pretty much down to filter.h plus noise. Jakub Kicinski (5): bpf: add header for enum bpf_cgroup_storage_type bpf: create a header for cgroup_storage_type() bpf: create a header for struct bpf_link bpf: remove the cgroup -> bpf header dependecy bpf: push down the bpf-link include include/linux/bpf-cgroup-storage.h | 17 +++++++++++++++++ include/linux/bpf-cgroup-types.h | 13 +++++++++++++ include/linux/bpf-cgroup.h | 13 +++---------- include/linux/bpf-link.h | 23 +++++++++++++++++++++++ include/linux/bpf.h | 19 ++----------------- kernel/bpf/bpf_iter.c | 1 + kernel/bpf/helpers.c | 1 + kernel/bpf/local_storage.c | 1 + kernel/bpf/syscall.c | 1 + net/core/dev.c | 1 + 10 files changed, 63 insertions(+), 27 deletions(-) create mode 100644 include/linux/bpf-cgroup-storage.h create mode 100644 include/linux/bpf-cgroup-types.h create mode 100644 include/linux/bpf-link.h -- 2.31.1
