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| author | Yonghong Song <yhs@fb.com> | 2020-07-23 21:41:19 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-07-26 06:16:33 +0300 |
| commit | d8793aca708602c676372b03d6493972457524af (patch) | |
| tree | e245a88b1cbd10418cd8eaf8aa1ab2aa732a6dd0 /tools/bpf/bpftool/Documentation | |
| parent | cd31039a7347610863aa8b77a9162048999723d0 (diff) | |
| download | linux-d8793aca708602c676372b03d6493972457524af.tar.xz | |
tools/bpftool: Add bpftool support for bpf map element iterator
The optional parameter "map MAP" can be added to "bpftool iter"
command to create a bpf iterator for map elements. For example,
bpftool iter pin ./prog.o /sys/fs/bpf/p1 map id 333
For map element bpf iterator "map MAP" parameter is required.
Otherwise, bpf link creation will return an error.
Quentin Monnet kindly provided bash-completion implementation
for new "map MAP" option.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184119.590799-1-yhs@fb.com
Diffstat (limited to 'tools/bpf/bpftool/Documentation')
| -rw-r--r-- | tools/bpf/bpftool/Documentation/bpftool-iter.rst | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-iter.rst b/tools/bpf/bpftool/Documentation/bpftool-iter.rst index 8dce698eab79..070ffacb42b5 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-iter.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-iter.rst @@ -17,14 +17,15 @@ SYNOPSIS ITER COMMANDS =================== -| **bpftool** **iter pin** *OBJ* *PATH* +| **bpftool** **iter pin** *OBJ* *PATH* [**map** *MAP*] | **bpftool** **iter help** | | *OBJ* := /a/file/of/bpf_iter_target.o +| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* } DESCRIPTION =========== - **bpftool iter pin** *OBJ* *PATH* + **bpftool iter pin** *OBJ* *PATH* [**map** *MAP*] A bpf iterator combines a kernel iterating of particular kernel data (e.g., tasks, bpf_maps, etc.) and a bpf program called for each kernel data object @@ -37,6 +38,12 @@ DESCRIPTION character ('.'), which is reserved for future extensions of *bpffs*. + Map element bpf iterator requires an additional parameter + *MAP* so bpf program can iterate over map elements for + that map. User can have a bpf program in kernel to run + with each map element, do checking, filtering, aggregation, + etc. without copying data to user space. + User can then *cat PATH* to see the bpf iterator output. **bpftool iter help** @@ -64,6 +71,13 @@ EXAMPLES Create a file-based bpf iterator from bpf_iter_netlink.o and pin it to /sys/fs/bpf/my_netlink +**# bpftool iter pin bpf_iter_hashmap.o /sys/fs/bpf/my_hashmap map id 20** + +:: + + Create a file-based bpf iterator from bpf_iter_hashmap.o and map with + id 20, and pin it to /sys/fs/bpf/my_hashmap + SEE ALSO ======== **bpf**\ (2), |