[PATCH 1/4] radix-tree: add end_index to support ranged iteration

From: Naoya Horiguchi
Date: Tue May 20 2014 - 22:27:58 EST


It's useful if we can run only over a specific index range of radix trees,
which this patch does. This patch changes only radix_tree_for_each_slot()
and radix_tree_for_each_tagged(), because we need it only for them for now.

ChangeLog:
- rebased onto v3.15-rc5, which has e a few new caller of radix_tree_for_each_slot(),
so apply this change them too.

Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
---
drivers/gpu/drm/qxl/qxl_ttm.c | 2 +-
include/linux/radix-tree.h | 27 ++++++++++++++++++++-------
kernel/irq/irqdomain.c | 2 +-
lib/radix-tree.c | 8 ++++----
mm/filemap.c | 8 ++++----
5 files changed, 30 insertions(+), 17 deletions(-)

diff --git v3.15-rc5.orig/drivers/gpu/drm/qxl/qxl_ttm.c v3.15-rc5/drivers/gpu/drm/qxl/qxl_ttm.c
index d52c27527b9a..d807e66fe308 100644
--- v3.15-rc5.orig/drivers/gpu/drm/qxl/qxl_ttm.c
+++ v3.15-rc5/drivers/gpu/drm/qxl/qxl_ttm.c
@@ -398,7 +398,7 @@ static int qxl_sync_obj_wait(void *sync_obj,
struct radix_tree_iter iter;
int release_id;

- radix_tree_for_each_slot(slot, &qfence->tree, &iter, 0) {
+ radix_tree_for_each_slot(slot, &qfence->tree, &iter, 0, ~0UL) {
struct qxl_release *release;

release_id = iter.index;
diff --git v3.15-rc5.orig/include/linux/radix-tree.h v3.15-rc5/include/linux/radix-tree.h
index 33170dbd9db4..88258c34371f 100644
--- v3.15-rc5.orig/include/linux/radix-tree.h
+++ v3.15-rc5/include/linux/radix-tree.h
@@ -312,6 +312,7 @@ static inline void radix_tree_preload_end(void)
* @index: index of current slot
* @next_index: next-to-last index for this chunk
* @tags: bit-mask for tag-iterating
+ * @end_index: last index to be scanned
*
* This radix tree iterator works in terms of "chunks" of slots. A chunk is a
* subinterval of slots contained within one radix tree leaf node. It is
@@ -324,6 +325,7 @@ struct radix_tree_iter {
unsigned long index;
unsigned long next_index;
unsigned long tags;
+ unsigned long end_index;
};

#define RADIX_TREE_ITER_TAG_MASK 0x00FF /* tag index in lower byte */
@@ -335,10 +337,12 @@ struct radix_tree_iter {
*
* @iter: pointer to iterator state
* @start: iteration starting index
+ * @end: iteration ending index
* Returns: NULL
*/
static __always_inline void **
-radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start)
+radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start,
+ unsigned long end)
{
/*
* Leave iter->tags uninitialized. radix_tree_next_chunk() will fill it
@@ -350,6 +354,7 @@ radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start)
*/
iter->index = 0;
iter->next_index = start;
+ iter->end_index = end;
return NULL;
}

@@ -399,6 +404,8 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
iter->tags >>= 1;
if (likely(iter->tags & 1ul)) {
iter->index++;
+ if (iter->index > iter->end_index)
+ return NULL;
return slot + 1;
}
if (!(flags & RADIX_TREE_ITER_CONTIG) && likely(iter->tags)) {
@@ -406,6 +413,8 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)

iter->tags >>= offset;
iter->index += offset + 1;
+ if (iter->index > iter->end_index)
+ return NULL;
return slot + offset + 1;
}
} else {
@@ -414,6 +423,8 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
while (size--) {
slot++;
iter->index++;
+ if (iter->index > iter->end_index)
+ return NULL;
if (likely(*slot))
return slot;
if (flags & RADIX_TREE_ITER_CONTIG) {
@@ -438,7 +449,7 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
* Locks can be released and reacquired between iterations.
*/
#define radix_tree_for_each_chunk(slot, root, iter, start, flags) \
- for (slot = radix_tree_iter_init(iter, start) ; \
+ for (slot = radix_tree_iter_init(iter, start, ~0UL) ; \
(slot = radix_tree_next_chunk(root, iter, flags)) ;)

/**
@@ -461,11 +472,12 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
* @root: the struct radix_tree_root pointer
* @iter: the struct radix_tree_iter pointer
* @start: iteration starting index
+ * @end: iteration ending index
*
* @slot points to radix tree slot, @iter->index contains its index.
*/
-#define radix_tree_for_each_slot(slot, root, iter, start) \
- for (slot = radix_tree_iter_init(iter, start) ; \
+#define radix_tree_for_each_slot(slot, root, iter, start, end) \
+ for (slot = radix_tree_iter_init(iter, start, end) ; \
slot || (slot = radix_tree_next_chunk(root, iter, 0)) ; \
slot = radix_tree_next_slot(slot, iter, 0))

@@ -480,7 +492,7 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
* @slot points to radix tree slot, @iter->index contains its index.
*/
#define radix_tree_for_each_contig(slot, root, iter, start) \
- for (slot = radix_tree_iter_init(iter, start) ; \
+ for (slot = radix_tree_iter_init(iter, start, ~0UL) ; \
slot || (slot = radix_tree_next_chunk(root, iter, \
RADIX_TREE_ITER_CONTIG)) ; \
slot = radix_tree_next_slot(slot, iter, \
@@ -493,12 +505,13 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
* @root: the struct radix_tree_root pointer
* @iter: the struct radix_tree_iter pointer
* @start: iteration starting index
+ * @end: iteration ending index
* @tag: tag index
*
* @slot points to radix tree slot, @iter->index contains its index.
*/
-#define radix_tree_for_each_tagged(slot, root, iter, start, tag) \
- for (slot = radix_tree_iter_init(iter, start) ; \
+#define radix_tree_for_each_tagged(slot, root, iter, start, end, tag) \
+ for (slot = radix_tree_iter_init(iter, start, end) ; \
slot || (slot = radix_tree_next_chunk(root, iter, \
RADIX_TREE_ITER_TAGGED | tag)) ; \
slot = radix_tree_next_slot(slot, iter, \
diff --git v3.15-rc5.orig/kernel/irq/irqdomain.c v3.15-rc5/kernel/irq/irqdomain.c
index f14033700c25..55fc49b412e1 100644
--- v3.15-rc5.orig/kernel/irq/irqdomain.c
+++ v3.15-rc5/kernel/irq/irqdomain.c
@@ -571,7 +571,7 @@ static int virq_debug_show(struct seq_file *m, void *private)
mutex_lock(&irq_domain_mutex);
list_for_each_entry(domain, &irq_domain_list, link) {
int count = 0;
- radix_tree_for_each_slot(slot, &domain->revmap_tree, &iter, 0)
+ radix_tree_for_each_slot(slot, &domain->revmap_tree, &iter, 0, ~0UL)
count++;
seq_printf(m, "%c%-16s %6u %10u %10u %s\n",
domain == irq_default_domain ? '*' : ' ', domain->name,
diff --git v3.15-rc5.orig/lib/radix-tree.c v3.15-rc5/lib/radix-tree.c
index 9599aa72d7a0..531fba8a81db 100644
--- v3.15-rc5.orig/lib/radix-tree.c
+++ v3.15-rc5/lib/radix-tree.c
@@ -1007,7 +1007,7 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
if (unlikely(!max_items))
return 0;

- radix_tree_for_each_slot(slot, root, &iter, first_index) {
+ radix_tree_for_each_slot(slot, root, &iter, first_index, ~0UL) {
results[ret] = indirect_to_ptr(rcu_dereference_raw(*slot));
if (!results[ret])
continue;
@@ -1049,7 +1049,7 @@ radix_tree_gang_lookup_slot(struct radix_tree_root *root,
if (unlikely(!max_items))
return 0;

- radix_tree_for_each_slot(slot, root, &iter, first_index) {
+ radix_tree_for_each_slot(slot, root, &iter, first_index, ~0UL) {
results[ret] = slot;
if (indices)
indices[ret] = iter.index;
@@ -1086,7 +1086,7 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
if (unlikely(!max_items))
return 0;

- radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) {
+ radix_tree_for_each_tagged(slot, root, &iter, first_index, ~0UL, tag) {
results[ret] = indirect_to_ptr(rcu_dereference_raw(*slot));
if (!results[ret])
continue;
@@ -1123,7 +1123,7 @@ radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,
if (unlikely(!max_items))
return 0;

- radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) {
+ radix_tree_for_each_tagged(slot, root, &iter, first_index, ~0UL, tag) {
results[ret] = slot;
if (++ret == max_items)
break;
diff --git v3.15-rc5.orig/mm/filemap.c v3.15-rc5/mm/filemap.c
index 000a220e2a41..d684e4cffe96 100644
--- v3.15-rc5.orig/mm/filemap.c
+++ v3.15-rc5/mm/filemap.c
@@ -1118,7 +1118,7 @@ unsigned find_get_entries(struct address_space *mapping,

rcu_read_lock();
restart:
- radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
+ radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start, ~0UL) {
struct page *page;
repeat:
page = radix_tree_deref_slot(slot);
@@ -1180,7 +1180,7 @@ unsigned find_get_pages(struct address_space *mapping, pgoff_t start,

rcu_read_lock();
restart:
- radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
+ radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start, ~0UL) {
struct page *page;
repeat:
page = radix_tree_deref_slot(slot);
@@ -1324,7 +1324,7 @@ unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
rcu_read_lock();
restart:
radix_tree_for_each_tagged(slot, &mapping->page_tree,
- &iter, *index, tag) {
+ &iter, *index, ~0UL, tag) {
struct page *page;
repeat:
page = radix_tree_deref_slot(slot);
@@ -2023,7 +2023,7 @@ void filemap_map_pages(struct vm_area_struct *vma, struct vm_fault *vmf)
pte_t *pte;

rcu_read_lock();
- radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, vmf->pgoff) {
+ radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, vmf->pgoff, ~0UL) {
if (iter.index > vmf->max_pgoff)
break;
repeat:
--
1.9.0

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