Re: [PATCH bpf-next] bpftool: Add BPF_F_QUERY_EFFECTIVE support in bpftool cgroup [show|tree]

[Jakub Kicinski <jakub.kicinski@netronome.com>]

On Tue, 25 Jun 2019 00:40:09 +0000, Alexei Starovoitov wrote:
> On 6/24/19 5:30 PM, Jakub Kicinski wrote:
> > On Tue, 25 Jun 2019 00:21:57 +0000, Alexei Starovoitov wrote:  
> >> On 6/24/19 5:16 PM, Jakub Kicinski wrote:  
> >>> On Mon, 24 Jun 2019 23:38:11 +0000, Alexei Starovoitov wrote:  
> >>>> I don't think this patch should be penalized.
> >>>> I'd rather see we fix them all.  
> >>>
> >>> So we are going to add this broken option just to remove it?
> >>> I don't understand.
> >>> I'm happy to spend the 15 minutes rewriting this if you don't
> >>> want to penalize Takshak.  
> >>
> >> hmm. I don't understand the 'broken' part.
> >> The only issue I see that it could have been local vs global,
> >> but they all should have been local.  
> > 
> > I don't think all of them.  Only --mapcompat and --bpffs.  bpffs could
> > be argued.  On mapcompat I must have not read the patch fully, I was
> > under the impression its a global libbpf flag :(
> > 
> > --json, --pretty, --nomount, --debug are global because they affect
> > global behaviour of bpftool.  The difference here is that we basically
> > add a syscall parameter as a global option.  
> 
> sure. I only disagreed about not touching older flags.
> --effective should be local.
> If follow up patch means 90% rewrite then revert is better.
> If it's 10% fixup then it's different story.

I see.  The local flag would not an option in getopt_long() sense, what
I was thinking was about adding an "effective" keyword:

# bpftool -e cgroup show /sys/fs/cgroup/cgroup-test-work-dir/cg1/

becomes:

# bpftool cgroup show /sys/fs/cgroup/cgroup-test-work-dir/cg1/ effective

That's how we handle flags for update calls for instance..

So I think a revert :(

> Takshak,
> could you check which way is cleaner? Revert and new patch or follow up fix?
> But bpftool doesn't have a way to do local, no?
> so it's kinda new feature and other flags should become local too.
> hence it feels more like follow up. Just my .02