Re: [PATCHv2 perf/core 5/7] tools lib bpf: Add bpf_program__pin()

From: Wangnan (F)
Date: Tue Jan 24 2017 - 21:19:49 EST

On 2017/1/25 9:16, Joe Stringer wrote:
On 24 January 2017 at 17:06, Wangnan (F) <wangnan0@xxxxxxxxxx> wrote:

On 2017/1/25 9:04, Wangnan (F) wrote:

On 2017/1/23 9:11, Joe Stringer wrote:
Add a new API to pin a BPF program to the filesystem. The user can
specify the path full path within a BPF filesystem to pin the program.
Programs with multiple instances are pinned as 'foo', 'foo_1', 'foo_2',
and so on.

Signed-off-by: Joe Stringer <joe@xxxxxxx>
v2: Don't automount BPF filesystem
Split program, map, object pinning into separate APIs and separate


+int bpf_program__pin(struct bpf_program *prog, const char *path)

In your next patch please let caller select one instance:

int bpf_program__pin(struct bpf_program *prog, int instance, const char
(please choose a better name)

Then your can wrap it with another function to pin all instances,
naming schema (%s_%d) there.

Then implement naming schema in bpf_object__pin like:


Is it possible to use directory tree instead?

I don't think objects have names, so let's assume an object with two
program instances named foo, and one map named bar.

A call of bpf_object__pin(obj, "/sys/fs/bpf/myobj") would mount with
the following files and directories:

Alternatively, if you want to control exactly where you want the
progs/maps to be pinned, you can call eg
bpf_program__pin_instance(prog, "/sys/fs/bpf/wherever", 0) and that
instance will be mounted to /sys/fs/bpf/wherever, or alternatively
bpf_program__pin(prog, "/sys/fs/bpf/foo"), and you will end up with

This looks pretty reasonable to me.

It looks good to me.

Thank you.