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From:   Namhyung Kim <namhyung@gmail.com>
Date:   Mon, 13 Feb 2023 09:43:23 -0800
Message-ID: <CAM9d7chx+azdxfNVVtaC_8eM2a57aBFa3hjh0TvjFt-6Xc7r7w@mail.gmail.com>
Subject: Re: [PATCH v2 7/7] tools/testing/selftests/bpf: replace open-coded 16
 with TASK_COMM_LEN
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Yafang Shao <laoar.shao@gmail.com>,
        John Stultz <jstultz@google.com>,
        Alexei Starovoitov <alexei.starovoitov@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Network Development <netdev@vger.kernel.org>,
        bpf <bpf@vger.kernel.org>,
        "linux-perf-use." <linux-perf-users@vger.kernel.org>,
        Linux-Fsdevel <linux-fsdevel@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        kernel test robot <oliver.sang@intel.com>,
        kbuild test robot <lkp@intel.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        David Hildenbrand <david@redhat.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>,
        Andrii Nakryiko <andrii.nakryiko@gmail.com>,
        Michal Miroslaw <mirq-linux@rere.qmqm.pl>,
        Peter Zijlstra <peterz@infradead.org>,
        Matthew Wilcox <willy@infradead.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Kees Cook <keescook@chromium.org>,
        Petr Mladek <pmladek@suse.com>,
        Kajetan Puchalski <kajetan.puchalski@arm.com>,
        Lukasz Luba <lukasz.luba@arm.com>,
        Qais Yousef <qyousef@google.com>,
        Daniele Di Proietto <ddiproietto@google.com>,
        Linus Torvalds <torvalds@linux-foundation.org>
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Hi Steve,

On Sat, Feb 11, 2023 at 8:07 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Sun, 12 Feb 2023 11:38:52 +0800
> Yafang Shao <laoar.shao@gmail.com> wrote:
>
> > > Actually, there are cases that this needs to be a number, as b3bc8547d3be6
> > > ("tracing: Have TRACE_DEFINE_ENUM affect trace event types as well") made
> > > it update fields as well as the printk fmt.
> > >
> >
> > It seems that TRACE_DEFINE_ENUM(TASK_COMM_LEN) in the trace events
> > header files would be a better fix.
>
> NACK! I much prefer the proper fix that adds the length.

Can we just have both enum and macro at the same time?
I guess the enum would fill the BTF and the macro would provide
backward compatibility.

Thanks,
Namhyung