Re: [PATCH] fs/proc/page: Refactoring to reduce code duplication.

[David Hildenbrand]

On 17.03.25 10:13, Liu Ye wrote:
> 在 2025/3/17 16:56, David Hildenbrand 写道:
> > On 17.03.25 09:01, Liu Ye wrote:
> > > From: Liu Ye <liuye@xxxxxxxxxx>
> > >
> > > The function kpageflags_read and kpagecgroup_read is quite similar
> > > to kpagecount_read. Consider refactoring common code into a helper
> > > function to reduce code duplication.
> > >
> > > Signed-off-by: Liu Ye <liuye@xxxxxxxxxx>
> > > ---
> > >    fs/proc/page.c | 158 ++++++++++++++++---------------------------------
> > >    1 file changed, 50 insertions(+), 108 deletions(-)
> > >
> > > diff --git a/fs/proc/page.c b/fs/proc/page.c
> > > index a55f5acefa97..f413016ebe67 100644
> > > --- a/fs/proc/page.c
> > > +++ b/fs/proc/page.c
> > > @@ -37,19 +37,17 @@ static inline unsigned long get_max_dump_pfn(void)
> > >    #endif
> > >    }
> > >    -/* /proc/kpagecount - an array exposing page mapcounts
> > > - *
> > > - * Each entry is a u64 representing the corresponding
> > > - * physical page mapcount.
> > > - */
> > > -static ssize_t kpagecount_read(struct file *file, char __user *buf,
> > > -                 size_t count, loff_t *ppos)
> > > +static ssize_t kpage_read(struct file *file, char __user *buf,
> > > +        size_t count, loff_t *ppos,
> > > +        u64 (*get_page_info)(struct page *))
> >
> > Can we just indicate using an enum which operation to perform, so we can avoid having+passing these functions?
> Like this? Good idea, I'll send a new patch later.
>
> enum kpage_operation {
>      KPAGE_FLAGS,
>      KPAGE_COUNT,
>      KPAGE_CGROUP,
> };
>
> static u64 get_page_info(struct page *page, enum kpage_operation op)
> {
>      switch (op) {
>      case KPAGE_FLAGS:
>          return stable_page_flags(page);
>      case KPAGE_COUNT:
>          return page_count(page);
>      case KPAGE_CGROUP:
>          return page_cgroup_ino(page);
>      default:
>          return 0;
>      }
> }


Likely it's best to inline get_page_info() into kpage_read() to just get 
rid of it.


--
Cheers,

David / dhildenb