Re: [PATCH v3] console: Add persistent scrollback buffers for all VGA consoles

From: Greg KH
Date: Tue Sep 27 2016 - 06:58:50 EST

On Mon, Sep 19, 2016 at 12:06:57AM +0200, Manuel Schölling wrote:
> Add a scrollback buffers for each VGA console. The benefit is that
> the scrollback history is not flushed when switching between consoles
> but is persistent.
> The buffers are allocated on demand when a new console is opened.
> It always annoys me when I switch back to a console and I can just
> read half of an error backtrace. This should fix issues like these.
> This breaks tools like clear_console that rely on flushing the
> scrollback history by switching back and forth between consoles
> which is why this feature is disabled by default.
> Use the escape sequence \e[3J instead for flushing the buffer.
> Signed-off-by: Manuel Schölling <manuel.schoelling@xxxxxx>
> ---
> Changes in v3:
> - Add config option for this feature
> - Fallback to old scrollback buffer if kcalloc() fails
> - Remove ioctl() call again and add documentation about existing
> escape sequence to flush the scrollback buffer
> Changes in v2:
> - Add ioctl() call to flush scrollback buffer
> - (Patch v2 was not labeled as such, sorry)
> ---
> drivers/video/console/Kconfig | 23 +++++-
> drivers/video/console/vgacon.c | 160 +++++++++++++++++++++++++++--------------
> 2 files changed, 128 insertions(+), 55 deletions(-)

I need someone else to at least test this, and give an acked-by for


greg k-h