lkml.org 
[lkml]   [2013]   [Jul]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC 3/4] Seperate page initialization into a separate function.
    On Fri, Jul 12, 2013 at 08:06:52PM -0700, Yinghai Lu wrote:
    > 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?

    Sure, but then I don't care for the name so much, but I can think on
    that some too.

    I think the feedback I was most hoping to receive was pertaining to a
    means for removing the PG_uninitialized2Mib flag entirely. If I could
    get rid of that and have some page-local way of knowing if it has not
    been initialized, I think this patch set would be much better.

    Robin


    \
     
     \ /
      Last update: 2013-07-15 06:01    [W:4.153 / U:0.132 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site