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

[Wangnan (F)]

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
> > > >       patches.
> > > > ---
> >
> > [SNIP]
> >
> > > > +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
> > > *path)
> > > (please choose a better name)
> > >
> > > Then your can wrap it with another function to pin all instances,
> > > implement
> > > naming schema (%s_%d) there.
> > >
> > > Then implement naming schema in bpf_object__pin like:
> > >
> > > %s/objectname_mapname
> > > %s/objectname_progname_%d
> > Is it possible to use directory tree instead?
> >
> > %s/object/mapname
> > %s/object/prog/instance
> 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:
> /sys/fs/bpf/myobj/foo/1
> /sys/fs/bpf/myobj/foo/2
> /sys/fs/bpf/myobj/bar
>
> 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
> /sys/fs/bpf/foo/{0,1}.
>
> This looks pretty reasonable to me.

It looks good to me.

Thank you.