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Commit 2f007e74 authored by Brice Goglin's avatar Brice Goglin Committed by Linus Torvalds
Browse files

mm: don't vmalloc a huge page_to_node array for do_pages_stat() 



do_pages_stat() does not need any page_to_node entry for real.  Just pass
the pointers to the user-space page address array and to the user-space
status array, and have do_pages_stat() traverse the former and fill the
latter directly.

Signed-off-by: default avatarBrice Goglin <Brice.Goglin@inria.fr>
Acked-by: default avatarChristoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e78bbfa8

mm/migrate.c

+25 −15
Original line number Original line Diff line number Diff line
@@ -906,25 +906,33 @@ static int do_move_pages(struct mm_struct *mm, struct page_to_node *pm, 
}

}





/*

/*

 * Determine the nodes of a list of pages. The addr in the pm array

 * Determine the nodes of an array of pages and store it in an array of status.

 * must have been set to the virtual address of which we want to determine

 * the node number.

 */

 */

static int do_pages_stat(struct mm_struct *mm, struct page_to_node *pm)

static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,

			 const void __user * __user *pages,

			 int __user *status)

{

{

	unsigned long i;

	int err;



	down_read(&mm->mmap_sem);

	down_read(&mm->mmap_sem);





	for ( ; pm->node != MAX_NUMNODES; pm++) {

	for (i = 0; i < nr_pages; i++) {

		const void __user *p;

		unsigned long addr;

		struct vm_area_struct *vma;

		struct vm_area_struct *vma;

		struct page *page;

		struct page *page;

		int err;





		err = -EFAULT;

		err = -EFAULT;

		vma = find_vma(mm, pm->addr);

		if (get_user(p, pages+i))

			goto out;

		addr = (unsigned long) p;



		vma = find_vma(mm, addr);

		if (!vma)

		if (!vma)

			goto set_status;

			goto set_status;





		page = follow_page(vma, pm->addr, 0);

		page = follow_page(vma, addr, 0);





		err = PTR_ERR(page);

		err = PTR_ERR(page);

		if (IS_ERR(page))

		if (IS_ERR(page))
@@ -937,11 +945,13 @@ static int do_pages_stat(struct mm_struct *mm, struct page_to_node *pm) 




		err = page_to_nid(page);

		err = page_to_nid(page);

set_status:

set_status:

		pm->status = err;

		put_user(err, status+i);

	}

	}

	err = 0;





out:

	up_read(&mm->mmap_sem);

	up_read(&mm->mmap_sem);

	return 0;

	return err;

}

}





/*

/*
@@ -997,6 +1007,10 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages, 
 	if (err)

 	if (err)

 		goto out2;

 		goto out2;





	if (!nodes) {

		err = do_pages_stat(mm, nr_pages, pages, status);

		goto out2;

	}





	task_nodes = cpuset_mems_allowed(task);

	task_nodes = cpuset_mems_allowed(task);
@@ -1045,11 +1059,7 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages, 
	/* End marker */

	/* End marker */

	pm[nr_pages].node = MAX_NUMNODES;

	pm[nr_pages].node = MAX_NUMNODES;





	if (nodes)

	err = do_move_pages(mm, pm, flags & MPOL_MF_MOVE_ALL);

	err = do_move_pages(mm, pm, flags & MPOL_MF_MOVE_ALL);

	else

		err = do_pages_stat(mm, pm);



	if (err >= 0)

	if (err >= 0)

		/* Return status information */

		/* Return status information */

		for (i = 0; i < nr_pages; i++)

		for (i = 0; i < nr_pages; i++)