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Date:   Tue, 3 Sep 2019 16:58:37 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     Petr Mladek <pmladek@suse.com>
Cc:     John Ogness <john.ogness@linutronix.de>,
        Andrea Parri <andrea.parri@amarulasolutions.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Brendan Higgins <brendanhiggins@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
Subject: Re: numlist API Re: [RFC PATCH v4 1/9] printk-rb: add a new printk
 ringbuffer implementation
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On (08/27/19 15:03), Petr Mladek wrote:
[..]
> > IMHO the API is sane. The only bizarre rule is that the numlist must
> > always have at least 1 node. But since the readers are non-consuming,
> > there is no real tragedy here.
> >
> > My goal is not to create some fabulous abstract data structure that
> > everyone should use. But I did try to minimize numlist (and dataring) to
> > only be concerned with clearly defined and minimal responsibilities
> > without imposing unnecessary restrictions on the user.
>
> The API is complicated because of the callbacks. It depends on a logic
> that is implemented externally. It makes it abstract to some extent.
>
> My view is that the API would be much cleaner and easier to review
> when the ID handling is "hardcoded" (helper functions). It could be
> made abstract anytime later when there is another user.

Makes sense.

> There should always be a reason why to make a code more complicated
> than necessary. It seems that the only reason is some theoretical
> future user and its theoretical requirements.

Agreed.

> Symmetry is really important. It is often sign of a good design.
>
> Simple and straightforward code is another important thing at
> this stage. The code is complicated and we need to make sure
> that it works. Any optimizations and generalization might
> be done later when needed.

Agreed.

	-ss