Commit 5f0af70a authored Nov 24, 2010 by David Sterba Committed by Linus Torvalds Nov 25, 2010

mm: remove call to find_vma in pagewalk for non-hugetlbfs



Commit d33b9f45 ("mm: hugetlb: fix hugepage memory leak in
walk_page_range()") introduces a check if a vma is a hugetlbfs one and
later in 5dc37642 ("mm hugetlb: add hugepage support to pagemap") it is
moved under #ifdef CONFIG_HUGETLB_PAGE but a needless find_vma call is
left behind and its result is not used anywhere else in the function.

The side-effect of caching vma for @addr inside walk->mm is neither
utilized in walk_page_range() nor in called functions.

Signed-off-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Matt Mackall <mpm@selenic.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e9959f0f

mm/pagewalk.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -139,7 +139,6 @@ int walk_page_range(unsigned long addr, unsigned long end,
		pgd_t *pgd;
		unsigned long next;
		int err = 0;
		struct vm_area_struct *vma;

		if (addr >= end)
		return err;
		@@ -149,15 +148,17 @@ int walk_page_range(unsigned long addr, unsigned long end,

		pgd = pgd_offset(walk->mm, addr);
		do {
		struct vm_area_struct *uninitialized_var(vma);

		next = pgd_addr_end(addr, end);

		#ifdef CONFIG_HUGETLB_PAGE
		/*
		* handle hugetlb vma individually because pagetable walk for
		* the hugetlb page is dependent on the architecture and
		* we can't handled it in the same manner as non-huge pages.
		*/
		vma = find_vma(walk->mm, addr);
		#ifdef CONFIG_HUGETLB_PAGE
		if (vma && is_vm_hugetlb_page(vma)) {
		if (vma->vm_end < next)
		next = vma->vm_end;

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