Re: [PATCH] mm/sparse: rename pfn_present() as pfn_to_section_present()

[David Hildenbrand <david@redhat.com>]

> Am 15.02.2020 um 07:19 schrieb Pingfan Liu <kernelfans@gmail.com>:
> 
> After introducing mem sub section concept, pfn_present() loses its literal
> meaning, and will not be necessary a truth on partial populated mem section.
> 
> Since all of the callers use it to judge an absent section, it is better to
> rename pfn_present() as pfn_to_section_present().

IMHO, the name is not any better.

pfn_in_present_section?

Cheers!

> 
> Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Leonardo Bras <leonardo@linux.ibm.com>
> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
> Cc: Nathan Lynch <nathanl@linux.ibm.com>
> To: linux-mm@kvack.org
> ---
> arch/powerpc/platforms/pseries/hotplug-memory.c | 2 +-
> drivers/base/node.c                             | 2 +-
> include/linux/mmzone.h                          | 4 ++--
> mm/page_ext.c                                   | 2 +-
> mm/shuffle.c                                    | 2 +-
> 5 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index a4d40a3..5088132 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -360,7 +360,7 @@ static bool lmb_is_removable(struct drmem_lmb *lmb)
> 
>    for (i = 0; i < scns_per_block; i++) {
>        pfn = PFN_DOWN(phys_addr);
> -        if (!pfn_present(pfn)) {
> +        if (!pfn_to_section_present(pfn)) {
>            phys_addr += MIN_MEMORY_BLOCK_SIZE;
>            continue;
>        }
> diff --git a/drivers/base/node.c b/drivers/base/node.c
> index 98a31ba..6f98568 100644
> --- a/drivers/base/node.c
> +++ b/drivers/base/node.c
> @@ -772,7 +772,7 @@ static int register_mem_sect_under_node(struct memory_block *mem_blk,
>         * memory block could have several absent sections from start.
>         * skip pfn range from absent section
>         */
> -        if (!pfn_present(pfn)) {
> +        if (!pfn_to_section_present(pfn)) {
>            pfn = round_down(pfn + PAGES_PER_SECTION,
>                     PAGES_PER_SECTION) - 1;
>            continue;
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index 462f687..eca2db7 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -1372,7 +1372,7 @@ static inline int pfn_valid(unsigned long pfn)
> }
> #endif
> 
> -static inline int pfn_present(unsigned long pfn)
> +static inline int pfn_to_section_present(unsigned long pfn)
> {
>    if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
>        return 0;
> @@ -1409,7 +1409,7 @@ void sparse_init(void);
> #else
> #define sparse_init()    do {} while (0)
> #define sparse_index_init(_sec, _nid)  do {} while (0)
> -#define pfn_present pfn_valid
> +#define pfn_to_section_present pfn_valid
> #define subsection_map_init(_pfn, _nr_pages) do {} while (0)
> #endif /* CONFIG_SPARSEMEM */
> 
> diff --git a/mm/page_ext.c b/mm/page_ext.c
> index 4ade843..df0e55e 100644
> --- a/mm/page_ext.c
> +++ b/mm/page_ext.c
> @@ -304,7 +304,7 @@ static int __meminit online_page_ext(unsigned long start_pfn,
>    }
> 
>    for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
> -        if (!pfn_present(pfn))
> +        if (!pfn_to_section_present(pfn))
>            continue;
>        fail = init_section_page_ext(pfn, nid);
>    }
> diff --git a/mm/shuffle.c b/mm/shuffle.c
> index b3fe97f..9242cc8 100644
> --- a/mm/shuffle.c
> +++ b/mm/shuffle.c
> @@ -72,7 +72,7 @@ static struct page * __meminit shuffle_valid_page(unsigned long pfn, int order)
>        return NULL;
> 
>    /* ...is the pfn in a present section or a hole? */
> -    if (!pfn_present(pfn))
> +    if (!pfn_to_section_present(pfn))
>        return NULL;
> 
>    /* ...is the page free and currently on a free_area list? */
> -- 
> 2.7.5
>