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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Wed, 14 Oct 2020 16:16:29 +0200
Message-ID: <CAMuHMdXHFFUrjRMEHnXXU8QQkgD9x_S6R3N0Q7Q4H2RSfy2GGw@mail.gmail.com>
Subject: Re: [GIT PULL] printk for 5.10 (includes lockless ringbuffer)
To:     Petr Mladek <pmladek@suse.com>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        John Ogness <john.ogness@linutronix.de>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Peter Zijlstra <peterz@infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Daniel Thompson <daniel.thompson@linaro.org>
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Hi Petr,

On Mon, Oct 12, 2020 at 4:50 PM Petr Mladek <pmladek@suse.com> wrote:
> - Fully lockless ringbuffer implementation, including the support for
>   continuous lines. It will allow to store and read messages in any
>   situation wihtout the risk of deadlocks and without the need
>   of temporary per-CPU buffers.

    linux-m68k-atari_defconfig$ bloat-o-meter vmlinux.old
vmlinux.lockless_ringbuffer
    add/remove: 39/16 grow/shrink: 9/15 up/down: 214075/-4362 (209713)
    Function                                     old     new   delta
    _printk_rb_static_infos                        -  180224 +180224
    _printk_rb_static_descs                        -   24576  +24576
    [...]

Seriously?!? Or am I being misled by the tools?

    linux-m68k-atari_defconfig$ size vmlinux.old vmlinux.lockless_ringbuffer
       text    data     bss     dec     hex filename
    3559108 941716 177772 4678596 4763c4 vmlinux.old
    3563922 1152496 175276 4891694 4aa42e vmlinux.lockless_ringbuffer

Apparently not...

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds