Re: [RFC PATCH v2 0/3] expose mapping wrprotect, fix fb_defio use

[Thomas Zimmermann]

Hi


Am 14.01.25 um 00:15 schrieb Lorenzo Stoakes:
[...]
> *** REVIEWERS NOTES: ***
>
> I do not have any hardware that uses fb_defio, so I'm asking for help with
> testing this series from those who do :) I have tested the mm side of this,
> and done a quick compile smoke test of the fb_defio side but this _very
> much_ requires testing on actual hardware to ensure everything behaves as
> expected.

With a recent Linux distro, you likely boot up graphics with simpledrm, 
which uses fb_defio as part of its console emulation. To test, boot the 
kernel with the 'nomodeset' parameter and write to /dev/fb0.

Best regards
Thomas

> This is based on Andrew's tree [0] in the mm-unstable branch - I was
> thinking it'd be best to go through the mm tree (with fb_defio maintainer
> approval, of course!) as it relies upon the mm changes to work correctly.
>
> [0]: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/
>
> RFC v2:
> * Updated Jaya Kumar's email on cc - the MAINTAINERS section is apparently incorrect.
> * Corrected rmap_walk_file() comment to refer to folios as per Matthew.
> * Reference folio->mapping rather than folio_mapping(folio) in rmap_walk_file()
>    as per Matthew.
> * Reference folio->index rather than folio_pgoff(folio) in rmap_walk_file() as
>    per Matthew.
> * Renamed rmap_wrprotect_file_page() to mapping_wrprotect_page() as per Matthew.
> * Fixed kerneldoc and moved to implementation as per Matthew.
> * Updated mapping_wrprotect_page() to take a struct page pointer as per David.
> * Removed folio lock when invoking mapping_wrprotect_page() in
>    fb_deferred_io_work() as per Matthew.
> * Removed compound_nr() in fb_deferred_io_work() as per Matthew.
>
> RFC v1:
> https://lore.kernel.org/all/1e452b5b65f15a9a5d0c2ed3f5f812fdd1367603.1736352361.git.lorenzo.stoakes@xxxxxxxxxx/
>
> Lorenzo Stoakes (3):
>    mm: refactor rmap_walk_file() to separate out traversal logic
>    mm: provide mapping_wrprotect_page() function
>    fb_defio: do not use deprecated page->mapping, index fields
>
>   drivers/video/fbdev/core/fb_defio.c |  38 ++-----
>   include/linux/fb.h                  |   1 +
>   include/linux/rmap.h                |   3 +
>   mm/rmap.c                           | 152 +++++++++++++++++++++++-----
>   4 files changed, 141 insertions(+), 53 deletions(-)
>
> --
> 2.48.0

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
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