Re: [RESEND][PATCH 0/6] Constify struct page arguments

From: William Kucharski
Date: Sat Apr 17 2021 - 03:16:58 EST


Looks good to me and I like the cleanup.

For the series:

Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx>

> On Apr 16, 2021, at 5:15 PM, Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> wrote:
>
> [I'm told that patches 2-6 did not make it to the list; resending and
> cc'ing lkml this time]
>
> While working on various solutions to the 32-bit struct page size
> regression, one of the problems I found was the networking stack expects
> to be able to pass const struct page pointers around, and the mm doesn't
> provide a lot of const-friendly functions to call. The root tangle of
> problems is that a lot of functions call VM_BUG_ON_PAGE(), which calls
> dump_page(), which calls a lot of functions which don't take a const
> struct page (but could be const).
>
> I have other things I need to work on, but I offer these patches as a few
> steps towards being able to make dump_page() take a const page pointer.
>
> Matthew Wilcox (Oracle) (6):
> mm: Make __dump_page static
> mm/debug: Factor PagePoisoned out of __dump_page
> mm/page_owner: Constify dump_page_owner
> mm: Make compound_head const-preserving
> mm: Constify get_pfnblock_flags_mask and get_pfnblock_migratetype
> mm: Constify page_count and page_ref_count
>
> include/linux/mmdebug.h | 3 +--
> include/linux/page-flags.h | 10 +++++-----
> include/linux/page_owner.h | 6 +++---
> include/linux/page_ref.h | 4 ++--
> include/linux/pageblock-flags.h | 2 +-
> mm/debug.c | 25 +++++++------------------
> mm/page_alloc.c | 16 ++++++++--------
> mm/page_owner.c | 2 +-
> 8 files changed, 28 insertions(+), 40 deletions(-)
>
> --
> 2.30.2
>
>