Commit 6b2dbba8 authored by Michel Lespinasse's avatar Michel Lespinasse Committed by Linus Torvalds
Browse files

mm: replace vma prio_tree with an interval tree 



Implement an interval tree as a replacement for the VMA prio_tree.  The
algorithms are similar to lib/interval_tree.c; however that code can't be
directly reused as the interval endpoints are not explicitly stored in the
VMA.  So instead, the common algorithm is moved into a template and the
details (node type, how to get interval endpoints from the node, etc) are
filled in using the C preprocessor.

Once the interval tree functions are available, using them as a
replacement to the VMA prio tree is a relatively simple, mechanical job.

Signed-off-by: default avatarMichel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fff3fd8a

arch/arm/mm/fault-armv.c

+1 −2
Original line number Diff line number Diff line
@@ -134,7 +134,6 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, 
{

	struct mm_struct *mm = vma->vm_mm;

	struct vm_area_struct *mpnt;

	struct prio_tree_iter iter;

	unsigned long offset;

	pgoff_t pgoff;

	int aliases = 0;
@@ -147,7 +146,7 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, 
	 * cache coherency.

	 */

	flush_dcache_mmap_lock(mapping);

	vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {

	vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {

		/*

		 * If this VMA is not in our MM, we can ignore it.

		 * Note that we intentionally mask out the VMA

arch/arm/mm/flush.c

+1 −2
Original line number Diff line number Diff line
@@ -196,7 +196,6 @@ static void __flush_dcache_aliases(struct address_space *mapping, struct page *p 
{

	struct mm_struct *mm = current->active_mm;

	struct vm_area_struct *mpnt;

	struct prio_tree_iter iter;

	pgoff_t pgoff;



	/*
@@ -208,7 +207,7 @@ static void __flush_dcache_aliases(struct address_space *mapping, struct page *p 
	pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);



	flush_dcache_mmap_lock(mapping);

	vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {

	vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {

		unsigned long offset;



		/*

arch/parisc/kernel/cache.c

+1 −2
Original line number Diff line number Diff line
@@ -276,7 +276,6 @@ void flush_dcache_page(struct page *page) 
{

	struct address_space *mapping = page_mapping(page);

	struct vm_area_struct *mpnt;

	struct prio_tree_iter iter;

	unsigned long offset;

	unsigned long addr, old_addr = 0;

	pgoff_t pgoff;
@@ -299,7 +298,7 @@ void flush_dcache_page(struct page *page) 
	 * to flush one address here for them all to become coherent */



	flush_dcache_mmap_lock(mapping);

	vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {

	vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {

		offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;

		addr = mpnt->vm_start + offset;

arch/x86/mm/hugetlbpage.c

+1 −2
Original line number Diff line number Diff line
@@ -71,7 +71,6 @@ huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) 
	struct address_space *mapping = vma->vm_file->f_mapping;

	pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +

			vma->vm_pgoff;

	struct prio_tree_iter iter;

	struct vm_area_struct *svma;

	unsigned long saddr;

	pte_t *spte = NULL;
@@ -81,7 +80,7 @@ huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) 
		return (pte_t *)pmd_alloc(mm, pud, addr);



	mutex_lock(&mapping->i_mmap_mutex);

	vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) {

	vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {

		if (svma == vma)

			continue;

fs/hugetlbfs/inode.c

+4 −5
Original line number Diff line number Diff line
@@ -397,17 +397,16 @@ static void hugetlbfs_evict_inode(struct inode *inode) 
}



static inline void

hugetlb_vmtruncate_list(struct prio_tree_root *root, pgoff_t pgoff)

hugetlb_vmtruncate_list(struct rb_root *root, pgoff_t pgoff)

{

	struct vm_area_struct *vma;

	struct prio_tree_iter iter;



	vma_prio_tree_foreach(vma, &iter, root, pgoff, ULONG_MAX) {

	vma_interval_tree_foreach(vma, root, pgoff, ULONG_MAX) {

		unsigned long v_offset;



		/*

		 * Can the expression below overflow on 32-bit arches?

		 * No, because the prio_tree returns us only those vmas

		 * No, because the interval tree returns us only those vmas

		 * which overlap the truncated area starting at pgoff,

		 * and no vma on a 32-bit arch can span beyond the 4GB.

		 */
@@ -432,7 +431,7 @@ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) 


	i_size_write(inode, offset);

	mutex_lock(&mapping->i_mmap_mutex);

	if (!prio_tree_empty(&mapping->i_mmap))

	if (!RB_EMPTY_ROOT(&mapping->i_mmap))

		hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);

	mutex_unlock(&mapping->i_mmap_mutex);

	truncate_hugepages(inode, offset);

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