Commit e0d85a36 authored Nov 02, 2011 by Andrea Arcangeli Committed by Linus Torvalds Nov 02, 2011

sparc: gup_pte_range() support THP based tail recounting



Up to this point the code assumed old refcounting for hugepages (pre-thp).
 This updates the code directly to the thp mapcount tail page refcounting.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0693bc9c

arch/sparc/mm/gup.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -12,6 +12,17 @@
		#include <linux/rwsem.h>
		#include <asm/pgtable.h>

		static inline void get_huge_page_tail(struct page *page)
		{
		/*
		* __split_huge_page_refcount() cannot run
		* from under us.
		*/
		VM_BUG_ON(page_mapcount(page) < 0);
		VM_BUG_ON(atomic_read(&page->_count) != 0);
		atomic_inc(&page->_mapcount);
		}

		/*
		* The performance critical leaf functions are made noinline otherwise gcc
		* inlines everything into a single function which results in too much
		@@ -56,6 +67,8 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
		put_page(head);
		return 0;
		}
		if (head != page)
		get_huge_page_tail(page);

		pages[*nr] = page;
		(*nr)++;