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Date:   Tue, 18 Jan 2022 10:33:23 +0200
From:   Pekka Paalanen <ppaalanen@gmail.com>
To:     Sven Schnelle <svens@stackframe.org>
Cc:     Thomas Zimmermann <tzimmermann@suse.de>,
        Helge Deller <deller@gmx.de>, linux-fbdev@vger.kernel.org,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] MAINTAINERS: Add Helge as fbdev maintainer
Message-ID: <20220118103323.4bae3a7d@eldfell>
In-Reply-To: <87bl0amc6s.fsf@x1.stackframe.org>
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On Mon, 17 Jan 2022 19:47:39 +0100
Sven Schnelle <svens@stackframe.org> wrote:

> I also tested the speed on my Thinkpad X1 with Intel graphics, and there
> a dmesg with 919 lines one the text console took about 2s to display. In
> x11, i measure 22ms. This might be unfair because encoding might be
> different, but i cannot confirm the 'memcpy' is faster than hardware
> blitting' point. I think if that would be the case, no-one would care
> about 2D acceleration.

I think that is an extremely unfair comparison, because a graphical
terminal app is not going to render every line of text streamed to it.
It probably renders only the final view alone if you simply run
'dmesg', skipping the first 800-900 lines completely.

Maybe fbcon should do the same when presented with a flood of text,
but I don't know how or why it works like it works. I assume in your
two second test you actually see some scrolling (animation) rather than
the final view? Or does it take 2 seconds just to update one screenful?

I doubt your fbcon and terminal window had height of 919 lines?


Thanks,
pq

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