Re: [RFC 3/4] Seperate page initialization into a separate function.

Yinghai Lu
2013-07-13T03:06:53Z

On Thu, Jul 11, 2013 at 7:03 PM, Robin Holt <holt@sgi.com> wrote:
> Currently, memmap_init_zone() has all the smarts for initializing a
> single page. When we convert to initializing pages in a 2MiB chunk,
> we will need to do this equivalent work from two separate places
> so we are breaking out a helper function.
>
> Signed-off-by: Robin Holt <holt@sgi.com>
> Signed-off-by: Nate Zimmer <nzimmer@sgi.com>
> To: "H. Peter Anvin" <hpa@zytor.com>
> To: Ingo Molnar <mingo@kernel.org>
> Cc: Linux Kernel <linux-kernel@vger.kernel.org>
> Cc: Linux MM <linux-mm@kvack.org>
> Cc: Rob Landley <rob@landley.net>
> Cc: Mike Travis <travis@sgi.com>
> Cc: Daniel J Blueman <daniel@numascale-asia.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Greg KH <gregkh@linuxfoundation.org>
> Cc: Yinghai Lu <yinghai@kernel.org>
> Cc: Mel Gorman <mgorman@suse.de>
> ---
> mm/mm_init.c | 2 +-
> mm/page_alloc.c | 75 +++++++++++++++++++++++++++++++++------------------------
> 2 files changed, 45 insertions(+), 32 deletions(-)
>
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index c280a02..be8a539 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -128,7 +128,7 @@ void __init mminit_verify_pageflags_layout(void)
> BUG_ON(or_mask != add_mask);
> }
>
> -void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
> +void mminit_verify_page_links(struct page *page, enum zone_type zone,
> unsigned long nid, unsigned long pfn)
> {
> BUG_ON(page_to_nid(page) != nid);
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index c3edb62..635b131 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -697,6 +697,49 @@ static void free_one_page(struct zone *zone, struct page *page, int order,
> spin_unlock(&zone->lock);
> }
>
> +static void __init_single_page(struct page *page, unsigned long zone, int nid, int reserved)
> +{
> + unsigned long pfn = page_to_pfn(page);
> + struct zone *z = &NODE_DATA(nid)->node_zones[zone];
> +
> + set_page_links(page, zone, nid, pfn);
> + mminit_verify_page_links(page, zone, nid, pfn);
> + init_page_count(page);
> + page_mapcount_reset(page);
> + page_nid_reset_last(page);
> + if (reserved) {
> + SetPageReserved(page);
> + } else {
> + ClearPageReserved(page);
> + set_page_count(page, 0);
> + }
> + /*
> + * Mark the block movable so that blocks are reserved for
> + * movable at startup. This will force kernel allocations
> + * to reserve their blocks rather than leaking throughout
> + * the address space during boot when many long-lived
> + * kernel allocations are made. Later some blocks near
> + * the start are marked MIGRATE_RESERVE by
> + * setup_zone_migrate_reserve()
> + *
> + * bitmap is created for zone's valid pfn range. but memmap
> + * can be created for invalid pages (for alignment)
> + * check here not to call set_pageblock_migratetype() against
> + * pfn out of zone.
> + */
> + if ((z->zone_start_pfn <= pfn)
> + && (pfn < zone_end_pfn(z))
> + && !(pfn & (pageblock_nr_pages - 1)))
> + set_pageblock_migratetype(page, MIGRATE_MOVABLE);
> +
> + INIT_LIST_HEAD(&page->lru);
> +#ifdef WANT_PAGE_VIRTUAL
> + /* The shift won't overflow because ZONE_NORMAL is below 4G. */
> + if (!is_highmem_idx(zone))
> + set_page_address(page, __va(pfn << PAGE_SHIFT));
> +#endif
> +}
> +
> static bool free_pages_prepare(struct page *page, unsigned int order)
> {
> int i;
> @@ -3934,37 +3977,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
> continue;
> }
> page = pfn_to_page(pfn);
> - set_page_links(page, zone, nid, pfn);
> - mminit_verify_page_links(page, zone, nid, pfn);
> - init_page_count(page);
> - page_mapcount_reset(page);
> - page_nid_reset_last(page);
> - SetPageReserved(page);
> - /*
> - * Mark the block movable so that blocks are reserved for
> - * movable at startup. This will force kernel allocations
> - * to reserve their blocks rather than leaking throughout
> - * the address space during boot when many long-lived
> - * kernel allocations are made. Later some blocks near
> - * the start are marked MIGRATE_RESERVE by
> - * setup_zone_migrate_reserve()
> - *
> - * bitmap is created for zone's valid pfn range. but memmap
> - * can be created for invalid pages (for alignment)
> - * check here not to call set_pageblock_migratetype() against
> - * pfn out of zone.
> - */
> - if ((z->zone_start_pfn <= pfn)
> - && (pfn < zone_end_pfn(z))
> - && !(pfn & (pageblock_nr_pages - 1)))
> - set_pageblock_migratetype(page, MIGRATE_MOVABLE);
> -
> - INIT_LIST_HEAD(&page->lru);
> -#ifdef WANT_PAGE_VIRTUAL
> - /* The shift won't overflow because ZONE_NORMAL is below 4G. */
> - if (!is_highmem_idx(zone))
> - set_page_address(page, __va(pfn << PAGE_SHIFT));
> -#endif
> + __init_single_page(page, zone, nid, 1);

Can you
move page = pfn_to_page(pfn) into __init_single_page
and pass pfn directly?

Yinghai