| Message ID | 20211023205154.6710-1-quentin@isovalent.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | bpftool: Switch to libbpf's hashmap for referencing BPF objects | expand |
On Sat, Oct 23, 2021 at 1:52 PM Quentin Monnet <quentin@isovalent.com> wrote: > > When listing BPF objects, bpftool can print a number of properties about > items holding references to these objects. For example, it can show pinned > paths for BPF programs, maps, and links; or programs and maps using a given > BTF object; or the names and PIDs of processes referencing BPF objects. To > collect this information, bpftool uses hash maps (to be clear: the data > structures, inside bpftool - we are not talking of BPF maps). It uses the > implementation available from the kernel, and picks it up from > tools/include/linux/hashtable.h. > > This patchset converts bpftool's hash maps to a distinct implementation > instead, the one coming with libbpf. The main motivation for this change is > that it should ease the path towards a potential out-of-tree mirror for > bpftool, like the one libbpf already has. Although it's not perfect to > depend on libbpf's internal components, bpftool is intimately tied with the > library anyway, and this looks better than depending too much on (non-UAPI) > kernel headers. > > The first two patches contain preparatory work on the Makefile and on the > initialisation of the hash maps for collecting pinned paths for objects. > Then the transition is split into several steps, one for each kind of > properties for which the collection is backed by hash maps. > > v2: > - Move hashmap cleanup for pinned paths for links from do_detach() to > do_show(). > - Handle errors on hashmap__append() (in three of the patches). > - Rename bpftool_hash_fn() and bpftool_equal_fn() as hash_fn_for_key_id() > and equal_fn_for_key_id(), respectively. > - Add curly braces for hashmap__for_each_key_entry() { } in > show_btf_plain() and show_btf_json(), where the flow was difficult to > read. > > Quentin Monnet (5): > bpftool: Remove Makefile dep. on $(LIBBPF) for $(LIBBPF_INTERNAL_HDRS) > bpftool: Do not expose and init hash maps for pinned path in main.c > bpftool: Switch to libbpf's hashmap for pinned paths of BPF objects > bpftool: Switch to libbpf's hashmap for programs/maps in BTF listing > bpftool: Switch to libbpf's hashmap for PIDs/names references > > tools/bpf/bpftool/Makefile | 12 ++-- > tools/bpf/bpftool/btf.c | 132 +++++++++++++++++-------------------- > tools/bpf/bpftool/common.c | 50 ++++++++------ > tools/bpf/bpftool/link.c | 45 ++++++++----- > tools/bpf/bpftool/main.c | 17 +---- > tools/bpf/bpftool/main.h | 54 +++++++-------- > tools/bpf/bpftool/map.c | 45 ++++++++----- > tools/bpf/bpftool/pids.c | 90 ++++++++++++++----------- > tools/bpf/bpftool/prog.c | 45 ++++++++----- > 9 files changed, 262 insertions(+), 228 deletions(-) > > -- > 2.30.2 > Applied to bpf-next, thanks.
When listing BPF objects, bpftool can print a number of properties about items holding references to these objects. For example, it can show pinned paths for BPF programs, maps, and links; or programs and maps using a given BTF object; or the names and PIDs of processes referencing BPF objects. To collect this information, bpftool uses hash maps (to be clear: the data structures, inside bpftool - we are not talking of BPF maps). It uses the implementation available from the kernel, and picks it up from tools/include/linux/hashtable.h. This patchset converts bpftool's hash maps to a distinct implementation instead, the one coming with libbpf. The main motivation for this change is that it should ease the path towards a potential out-of-tree mirror for bpftool, like the one libbpf already has. Although it's not perfect to depend on libbpf's internal components, bpftool is intimately tied with the library anyway, and this looks better than depending too much on (non-UAPI) kernel headers. The first two patches contain preparatory work on the Makefile and on the initialisation of the hash maps for collecting pinned paths for objects. Then the transition is split into several steps, one for each kind of properties for which the collection is backed by hash maps. v2: - Move hashmap cleanup for pinned paths for links from do_detach() to do_show(). - Handle errors on hashmap__append() (in three of the patches). - Rename bpftool_hash_fn() and bpftool_equal_fn() as hash_fn_for_key_id() and equal_fn_for_key_id(), respectively. - Add curly braces for hashmap__for_each_key_entry() { } in show_btf_plain() and show_btf_json(), where the flow was difficult to read. Quentin Monnet (5): bpftool: Remove Makefile dep. on $(LIBBPF) for $(LIBBPF_INTERNAL_HDRS) bpftool: Do not expose and init hash maps for pinned path in main.c bpftool: Switch to libbpf's hashmap for pinned paths of BPF objects bpftool: Switch to libbpf's hashmap for programs/maps in BTF listing bpftool: Switch to libbpf's hashmap for PIDs/names references tools/bpf/bpftool/Makefile | 12 ++-- tools/bpf/bpftool/btf.c | 132 +++++++++++++++++-------------------- tools/bpf/bpftool/common.c | 50 ++++++++------ tools/bpf/bpftool/link.c | 45 ++++++++----- tools/bpf/bpftool/main.c | 17 +---- tools/bpf/bpftool/main.h | 54 +++++++-------- tools/bpf/bpftool/map.c | 45 ++++++++----- tools/bpf/bpftool/pids.c | 90 ++++++++++++++----------- tools/bpf/bpftool/prog.c | 45 ++++++++----- 9 files changed, 262 insertions(+), 228 deletions(-)