summaryrefslogtreecommitdiff
path: root/mm
diff options
context:
space:
mode:
Diffstat (limited to 'mm')
-rw-r--r--mm/Kconfig4
-rw-r--r--mm/filemap.c724
-rw-r--r--mm/huge_memory.c17
-rw-r--r--mm/khugepaged.c178
-rw-r--r--mm/madvise.c2
-rw-r--r--mm/memcontrol.c2
-rw-r--r--mm/memfd.c105
-rw-r--r--mm/migrate.c48
-rw-r--r--mm/mincore.c2
-rw-r--r--mm/page-writeback.c72
-rw-r--r--mm/readahead.c10
-rw-r--r--mm/shmem.c193
-rw-r--r--mm/swap.c6
-rw-r--r--mm/swap_state.c119
-rw-r--r--mm/truncate.c27
-rw-r--r--mm/vmscan.c10
-rw-r--r--mm/workingset.c68
17 files changed, 647 insertions, 940 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index de64ea658716..02301a89089e 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -379,7 +379,7 @@ config TRANSPARENT_HUGEPAGE
bool "Transparent Hugepage Support"
depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE
select COMPACTION
- select RADIX_TREE_MULTIORDER
+ select XARRAY_MULTI
help
Transparent Hugepages allows the kernel to use huge pages and
huge tlb transparently to the applications whenever possible.
@@ -671,7 +671,7 @@ config ZONE_DEVICE
depends on MEMORY_HOTREMOVE
depends on SPARSEMEM_VMEMMAP
depends on ARCH_HAS_ZONE_DEVICE
- select RADIX_TREE_MULTIORDER
+ select XARRAY_MULTI
help
Device memory hotplug support allows for establishing pmem,
diff --git a/mm/filemap.c b/mm/filemap.c
index 3968da1f7f5a..218d0b2ec82d 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -113,60 +113,26 @@
* ->tasklist_lock (memory_failure, collect_procs_ao)
*/
-static int page_cache_tree_insert(struct address_space *mapping,
- struct page *page, void **shadowp)
-{
- struct radix_tree_node *node;
- void **slot;
- int error;
-
- error = __radix_tree_create(&mapping->i_pages, page->index, 0,
- &node, &slot);
- if (error)
- return error;
- if (*slot) {
- void *p;
-
- p = radix_tree_deref_slot_protected(slot,
- &mapping->i_pages.xa_lock);
- if (!radix_tree_exceptional_entry(p))
- return -EEXIST;
-
- mapping->nrexceptional--;
- if (shadowp)
- *shadowp = p;
- }
- __radix_tree_replace(&mapping->i_pages, node, slot, page,
- workingset_lookup_update(mapping));
- mapping->nrpages++;
- return 0;
-}
-
-static void page_cache_tree_delete(struct address_space *mapping,
+static void page_cache_delete(struct address_space *mapping,
struct page *page, void *shadow)
{
- int i, nr;
+ XA_STATE(xas, &mapping->i_pages, page->index);
+ unsigned int nr = 1;
+
+ mapping_set_update(&xas, mapping);
- /* hugetlb pages are represented by one entry in the radix tree */
- nr = PageHuge(page) ? 1 : hpage_nr_pages(page);
+ /* hugetlb pages are represented by a single entry in the xarray */
+ if (!PageHuge(page)) {
+ xas_set_order(&xas, page->index, compound_order(page));
+ nr = 1U << compound_order(page);
+ }
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageTail(page), page);
VM_BUG_ON_PAGE(nr != 1 && shadow, page);
- for (i = 0; i < nr; i++) {
- struct radix_tree_node *node;
- void **slot;
-
- __radix_tree_lookup(&mapping->i_pages, page->index + i,
- &node, &slot);
-
- VM_BUG_ON_PAGE(!node && nr != 1, page);
-
- radix_tree_clear_tags(&mapping->i_pages, node, slot);
- __radix_tree_replace(&mapping->i_pages, node, slot, shadow,
- workingset_lookup_update(mapping));
- }
+ xas_store(&xas, shadow);
+ xas_init_marks(&xas);
page->mapping = NULL;
/* Leave page->index set: truncation lookup relies upon it */
@@ -265,7 +231,7 @@ void __delete_from_page_cache(struct page *page, void *shadow)
trace_mm_filemap_delete_from_page_cache(page);
unaccount_page_cache_page(mapping, page);
- page_cache_tree_delete(mapping, page, shadow);
+ page_cache_delete(mapping, page, shadow);
}
static void page_cache_free_page(struct address_space *mapping,
@@ -308,7 +274,7 @@ void delete_from_page_cache(struct page *page)
EXPORT_SYMBOL(delete_from_page_cache);
/*
- * page_cache_tree_delete_batch - delete several pages from page cache
+ * page_cache_delete_batch - delete several pages from page cache
* @mapping: the mapping to which pages belong
* @pvec: pagevec with pages to delete
*
@@ -321,24 +287,19 @@ EXPORT_SYMBOL(delete_from_page_cache);
*
* The function expects the i_pages lock to be held.
*/
-static void
-page_cache_tree_delete_batch(struct address_space *mapping,
+static void page_cache_delete_batch(struct address_space *mapping,
struct pagevec *pvec)
{
- struct radix_tree_iter iter;
- void **slot;
+ XA_STATE(xas, &mapping->i_pages, pvec->pages[0]->index);
int total_pages = 0;
int i = 0, tail_pages = 0;
struct page *page;
- pgoff_t start;
- start = pvec->pages[0]->index;
- radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
+ mapping_set_update(&xas, mapping);
+ xas_for_each(&xas, page, ULONG_MAX) {
if (i >= pagevec_count(pvec) && !tail_pages)
break;
- page = radix_tree_deref_slot_protected(slot,
- &mapping->i_pages.xa_lock);
- if (radix_tree_exceptional_entry(page))
+ if (xa_is_value(page))
continue;
if (!tail_pages) {
/*
@@ -346,8 +307,11 @@ page_cache_tree_delete_batch(struct address_space *mapping,
* have our pages locked so they are protected from
* being removed.
*/
- if (page != pvec->pages[i])
+ if (page != pvec->pages[i]) {
+ VM_BUG_ON_PAGE(page->index >
+ pvec->pages[i]->index, page);
continue;
+ }
WARN_ON_ONCE(!PageLocked(page));
if (PageTransHuge(page) && !PageHuge(page))
tail_pages = HPAGE_PMD_NR - 1;
@@ -358,11 +322,11 @@ page_cache_tree_delete_batch(struct address_space *mapping,
*/
i++;
} else {
+ VM_BUG_ON_PAGE(page->index + HPAGE_PMD_NR - tail_pages
+ != pvec->pages[i]->index, page);
tail_pages--;
}
- radix_tree_clear_tags(&mapping->i_pages, iter.node, slot);
- __radix_tree_replace(&mapping->i_pages, iter.node, slot, NULL,
- workingset_lookup_update(mapping));
+ xas_store(&xas, NULL);
total_pages++;
}
mapping->nrpages -= total_pages;
@@ -383,7 +347,7 @@ void delete_from_page_cache_batch(struct address_space *mapping,
unaccount_page_cache_page(mapping, pvec->pages[i]);
}
- page_cache_tree_delete_batch(mapping, pvec);
+ page_cache_delete_batch(mapping, pvec);
xa_unlock_irqrestore(&mapping->i_pages, flags);
for (i = 0; i < pagevec_count(pvec); i++)
@@ -493,20 +457,31 @@ EXPORT_SYMBOL(filemap_flush);
bool filemap_range_has_page(struct address_space *mapping,
loff_t start_byte, loff_t end_byte)
{
- pgoff_t index = start_byte >> PAGE_SHIFT;
- pgoff_t end = end_byte >> PAGE_SHIFT;
struct page *page;
+ XA_STATE(xas, &mapping->i_pages, start_byte >> PAGE_SHIFT);
+ pgoff_t max = end_byte >> PAGE_SHIFT;
if (end_byte < start_byte)
return false;
- if (mapping->nrpages == 0)
- return false;
+ rcu_read_lock();
+ for (;;) {
+ page = xas_find(&xas, max);
+ if (xas_retry(&xas, page))
+ continue;
+ /* Shadow entries don't count */
+ if (xa_is_value(page))
+ continue;
+ /*
+ * We don't need to try to pin this page; we're about to
+ * release the RCU lock anyway. It is enough to know that
+ * there was a page here recently.
+ */
+ break;
+ }
+ rcu_read_unlock();
- if (!find_get_pages_range(mapping, &index, end, 1, &page))
- return false;
- put_page(page);
- return true;
+ return page != NULL;
}
EXPORT_SYMBOL(filemap_range_has_page);
@@ -777,51 +752,44 @@ EXPORT_SYMBOL(file_write_and_wait_range);
* locked. This function does not add the new page to the LRU, the
* caller must do that.
*
- * The remove + add is atomic. The only way this function can fail is
- * memory allocation failure.
+ * The remove + add is atomic. This function cannot fail.
*/
int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
{
- int error;
+ struct address_space *mapping = old->mapping;
+ void (*freepage)(struct page *) = mapping->a_ops->freepage;
+ pgoff_t offset = old->index;
+ XA_STATE(xas, &mapping->i_pages, offset);
+ unsigned long flags;
VM_BUG_ON_PAGE(!PageLocked(old), old);
VM_BUG_ON_PAGE(!PageLocked(new), new);
VM_BUG_ON_PAGE(new->mapping, new);
- error = radix_tree_preload(gfp_mask & GFP_RECLAIM_MASK);
- if (!error) {
- struct address_space *mapping = old->mapping;
- void (*freepage)(struct page *);
- unsigned long flags;
-
- pgoff_t offset = old->index;
- freepage = mapping->a_ops->freepage;
-
- get_page(new);
- new->mapping = mapping;
- new->index = offset;
+ get_page(new);
+ new->mapping = mapping;
+ new->index = offset;
- xa_lock_irqsave(&mapping->i_pages, flags);
- __delete_from_page_cache(old, NULL);
- error = page_cache_tree_insert(mapping, new, NULL);
- BUG_ON(error);
+ xas_lock_irqsave(&xas, flags);
+ xas_store(&xas, new);
- /*
- * hugetlb pages do not participate in page cache accounting.
- */
- if (!PageHuge(new))
- __inc_node_page_state(new, NR_FILE_PAGES);
- if (PageSwapBacked(new))
- __inc_node_page_state(new, NR_SHMEM);
- xa_unlock_irqrestore(&mapping->i_pages, flags);
- mem_cgroup_migrate(old, new);
- radix_tree_preload_end();
- if (freepage)
- freepage(old);
- put_page(old);
- }
+ old->mapping = NULL;
+ /* hugetlb pages do not participate in page cache accounting. */
+ if (!PageHuge(old))
+ __dec_node_page_state(new, NR_FILE_PAGES);
+ if (!PageHuge(new))
+ __inc_node_page_state(new, NR_FILE_PAGES);
+ if (PageSwapBacked(old))
+ __dec_node_page_state(new, NR_SHMEM);
+ if (PageSwapBacked(new))
+ __inc_node_page_state(new, NR_SHMEM);
+ xas_unlock_irqrestore(&xas, flags);
+ mem_cgroup_migrate(old, new);
+ if (freepage)
+ freepage(old);
+ put_page(old);
- return error;
+ return 0;
}
EXPORT_SYMBOL_GPL(replace_page_cache_page);
@@ -830,12 +798,15 @@ static int __add_to_page_cache_locked(struct page *page,
pgoff_t offset, gfp_t gfp_mask,
void **shadowp)
{
+ XA_STATE(xas, &mapping->i_pages, offset);
int huge = PageHuge(page);
struct mem_cgroup *memcg;
int error;
+ void *old;
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageSwapBacked(page), page);
+ mapping_set_update(&xas, mapping);
if (!huge) {
error = mem_cgroup_try_charge(page, current->mm,
@@ -844,39 +815,47 @@ static int __add_to_page_cache_locked(struct page *page,
return error;
}
- error = radix_tree_maybe_preload(gfp_mask & GFP_RECLAIM_MASK);
- if (error) {
- if (!huge)
- mem_cgroup_cancel_charge(page, memcg, false);
- return error;
- }
-
get_page(page);
page->mapping = mapping;
page->index = offset;
- xa_lock_irq(&mapping->i_pages);
- error = page_cache_tree_insert(mapping, page, shadowp);
- radix_tree_preload_end();
- if (unlikely(error))
- goto err_insert;
+ do {
+ xas_lock_irq(&xas);
+ old = xas_load(&xas);
+ if (old && !xa_is_value(old))
+ xas_set_err(&xas, -EEXIST);
+ xas_store(&xas, page);
+ if (xas_error(&xas))
+ goto unlock;
+
+ if (xa_is_value(old)) {
+ mapping->nrexceptional--;
+ if (shadowp)
+ *shadowp = old;
+ }
+ mapping->nrpages++;
+
+ /* hugetlb pages do not participate in page cache accounting */
+ if (!huge)
+ __inc_node_page_state(page, NR_FILE_PAGES);
+unlock:
+ xas_unlock_irq(&xas);
+ } while (xas_nomem(&xas, gfp_mask & GFP_RECLAIM_MASK));
+
+ if (xas_error(&xas))
+ goto error;
- /* hugetlb pages do not participate in page cache accounting. */
- if (!huge)
- __inc_node_page_state(page, NR_FILE_PAGES);
- xa_unlock_irq(&mapping->i_pages);
if (!huge)
mem_cgroup_commit_charge(page, memcg, false, false);
trace_mm_filemap_add_to_page_cache(page);
return 0;
-err_insert:
+error:
page->mapping = NULL;
/* Leave page->index set: truncation relies upon it */
- xa_unlock_irq(&mapping->i_pages);
if (!huge)
mem_cgroup_cancel_charge(page, memcg, false);
put_page(page);
- return error;
+ return xas_error(&xas);
}
/**
@@ -1341,86 +1320,76 @@ int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
}
/**
- * page_cache_next_hole - find the next hole (not-present entry)
- * @mapping: mapping
- * @index: index
- * @max_scan: maximum range to search
- *
- * Search the set [index, min(index+max_scan-1, MAX_INDEX)] for the
- * lowest indexed hole.
- *
- * Returns: the index of the hole if found, otherwise returns an index
- * outside of the set specified (in which case 'return - index >=
- * max_scan' will be true). In rare cases of index wrap-around, 0 will
- * be returned.
- *
- * page_cache_next_hole may be called under rcu_read_lock. However,
- * like radix_tree_gang_lookup, this will not atomically search a
- * snapshot of the tree at a single point in time. For example, if a
- * hole is created at index 5, then subsequently a hole is created at
- * index 10, page_cache_next_hole covering both indexes may return 10
- * if called under rcu_read_lock.
+ * page_cache_next_miss() - Find the next gap in the page cache.
+ * @mapping: Mapping.
+ * @index: Index.
+ * @max_scan: Maximum range to search.
+ *
+ * Search the range [index, min(index + max_scan - 1, ULONG_MAX)] for the
+ * gap with the lowest index.
+ *
+ * This function may be called under the rcu_read_lock. However, this will
+ * not atomically search a snapshot of the cache at a single point in time.
+ * For example, if a gap is created at index 5, then subsequently a gap is
+ * created at index 10, page_cache_next_miss covering both indices may
+ * return 10 if called under the rcu_read_lock.
+ *
+ * Return: The index of the gap if found, otherwise an index outside the
+ * range specified (in which case 'return - index >= max_scan' will be true).
+ * In the rare case of index wrap-around, 0 will be returned.
*/
-pgoff_t page_cache_next_hole(struct address_space *mapping,
+pgoff_t page_cache_next_miss(struct address_space *mapping,
pgoff_t index, unsigned long max_scan)
{
- unsigned long i;
-
- for (i = 0; i < max_scan; i++) {
- struct page *page;
+ XA_STATE(xas, &mapping->i_pages, index);
- page = radix_tree_lookup(&mapping->i_pages, index);
- if (!page || radix_tree_exceptional_entry(page))
+ while (max_scan--) {
+ void *entry = xas_next(&xas);
+ if (!entry || xa_is_value(entry))
break;
- index++;
- if (index == 0)
+ if (xas.xa_index == 0)
break;
}
- return index;
+ return xas.xa_index;
}
-EXPORT_SYMBOL(page_cache_next_hole);
+EXPORT_SYMBOL(page_cache_next_miss);
/**
- * page_cache_prev_hole - find the prev hole (not-present entry)
- * @mapping: mapping
- * @index: index
- * @max_scan: maximum range to search
- *
- * Search backwards in the range [max(index-max_scan+1, 0), index] for
- * the first hole.
- *
- * Returns: the index of the hole if found, otherwise returns an index
- * outside of the set specified (in which case 'index - return >=
- * max_scan' will be true). In rare cases of wrap-around, ULONG_MAX
- * will be returned.
- *
- * page_cache_prev_hole may be called under rcu_read_lock. However,
- * like radix_tree_gang_lookup, this will not atomically search a
- * snapshot of the tree at a single point in time. For example, if a
- * hole is created at index 10, then subsequently a hole is created at
- * index 5, page_cache_prev_hole covering both indexes may return 5 if
- * called under rcu_read_lock.
+ * page_cache_prev_miss() - Find the next gap in the page cache.
+ * @mapping: Mapping.
+ * @index: Index.
+ * @max_scan: Maximum range to search.
+ *
+ * Search the range [max(index - max_scan + 1, 0), index] for the
+ * gap with the highest index.
+ *
+ * This function may be called under the rcu_read_lock. However, this will
+ * not atomically search a snapshot of the cache at a single point in time.
+ * For example, if a gap is created at index 10, then subsequently a gap is
+ * created at index 5, page_cache_prev_miss() covering both indices may
+ * return 5 if called under the rcu_read_lock.
+ *
+ * Return: The index of the gap if found, otherwise an index outside the
+ * range specified (in which case 'index - return >= max_scan' will be true).
+ * In the rare case of wrap-around, ULONG_MAX will be returned.
*/
-pgoff_t page_cache_prev_hole(struct address_space *mapping,
+pgoff_t page_cache_prev_miss(struct address_space *mapping,
pgoff_t index, unsigned long max_scan)
{
- unsigned long i;
-
- for (i = 0; i < max_scan; i++) {
- struct page *page;
+ XA_STATE(xas, &mapping->i_pages, index);
- page = radix_tree_lookup(&mapping->i_pages, index);
- if (!page || radix_tree_exceptional_entry(page))
+ while (max_scan--) {
+ void *entry = xas_prev(&xas);
+ if (!entry || xa_is_value(entry))
break;
- index--;
- if (index == ULONG_MAX)
+ if (xas.xa_index == ULONG_MAX)
break;
}
- return index;
+ return xas.xa_index;
}
-EXPORT_SYMBOL(page_cache_prev_hole);
+EXPORT_SYMBOL(page_cache_prev_miss);
/**
* find_get_entry - find and get a page cache entry
@@ -1437,47 +1406,40 @@ EXPORT_SYMBOL(page_cache_prev_hole);
*/
struct page *find_get_entry(struct address_space *mapping, pgoff_t offset)
{
- void **pagep;
+ XA_STATE(xas, &mapping->i_pages, offset);
struct page *head, *page;
rcu_read_lock();
repeat:
- page = NULL;
- pagep = radix_tree_lookup_slot(&mapping->i_pages, offset);
- if (pagep) {
- page = radix_tree_deref_slot(pagep);
- if (unlikely(!page))
- goto out;
- if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page))
- goto repeat;
- /*
- * A shadow entry of a recently evicted page,
- * or a swap entry from shmem/tmpfs. Return
- * it without attempting to raise page count.
- */
- goto out;
- }
+ xas_reset(&xas);
+ page = xas_load(&xas);
+ if (xas_retry(&xas, page))
+ goto repeat;
+ /*
+ * A shadow entry of a recently evicted page, or a swap entry from
+ * shmem/tmpfs. Return it without attempting to raise page count.
+ */
+ if (!page || xa_is_value(page))
+ goto out;
- head = compound_head(page);
- if (!page_cache_get_speculative(head))
- goto repeat;
+ head = compound_head(page);
+ if (!page_cache_get_speculative(head))
+ goto repeat;
- /* The page was split under us? */
- if (compound_head(page) != head) {
- put_page(head);
- goto repeat;
- }
+ /* The page was split under us? */
+ if (compound_head(page) != head) {
+ put_page(head);
+ goto repeat;
+ }
- /*
- * Has the page moved?
- * This is part of the lockless pagecache protocol. See
- * include/linux/pagemap.h for details.
- */
- if (unlikely(page != *pagep)) {
- put_page(head);
- goto repeat;
- }
+ /*
+ * Has the page moved?
+ * This is part of the lockless pagecache protocol. See
+ * include/linux/pagemap.h for details.
+ */
+ if (unlikely(page != xas_reload(&xas))) {
+ put_page(head);
+ goto repeat;
}
out:
rcu_read_unlock();
@@ -1508,7 +1470,7 @@ struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset)
repeat:
page = find_get_entry(mapping, offset);
- if (page && !radix_tree_exception(page)) {
+ if (page && !xa_is_value(page)) {
lock_page(page);
/* Has the page been truncated? */
if (unlikely(page_mapping(page) != mapping)) {
@@ -1554,7 +1516,7 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
repeat:
page = find_get_entry(mapping, offset);
- if (radix_tree_exceptional_entry(page))
+ if (xa_is_value(page))
page = NULL;
if (!page)
goto no_page;
@@ -1640,53 +1602,48 @@ unsigned find_get_entries(struct address_space *mapping,
pgoff_t start, unsigned int nr_entries,
struct page **entries, pgoff_t *indices)
{
- void **slot;
+ XA_STATE(xas, &mapping->i_pages, start);
+ struct page *page;
unsigned int ret = 0;
- struct radix_tree_iter iter;
if (!nr_entries)
return 0;
rcu_read_lock();
- radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
- struct page *head, *page;
-repeat:
- page = radix_tree_deref_slot(slot);
- if (unlikely(!page))
+ xas_for_each(&xas, page, ULONG_MAX) {
+ struct page *head;
+ if (xas_retry(&xas, page))
continue;
- if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
- continue;
- }
- /*
- * A shadow entry of a recently evicted page, a swap
- * entry from shmem/tmpfs or a DAX entry. Return it
- * without attempting to raise page count.
- */
+ /*
+ * A shadow entry of a recently evicted page, a swap
+ * entry from shmem/tmpfs or a DAX entry. Return it
+ * without attempting to raise page count.
+ */
+ if (xa_is_value(page))
goto export;
- }
head = compound_head(page);
if (!page_cache_get_speculative(head))
- goto repeat;
+ goto retry;
/* The page was split under us? */
- if (compound_head(page) != head) {
- put_page(head);
- goto repeat;
- }
+ if (compound_head(page) != head)
+ goto put_page;
/* Has the page moved? */
- if (unlikely(page != *slot)) {
- put_page(head);
- goto repeat;
- }
+ if (unlikely(page != xas_reload(&xas)))
+ goto put_page;
+
export:
- indices[ret] = iter.index;
+ indices[ret] = xas.xa_index;
entries[ret] = page;
if (++ret == nr_entries)
break;
+ continue;
+put_page:
+ put_page(head);
+retry:
+ xas_reset(&xas);
}
rcu_read_unlock();
return ret;
@@ -1717,64 +1674,50 @@ unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
pgoff_t end, unsigned int nr_pages,
struct page **pages)
{
- struct radix_tree_iter iter;
- void **slot;
+ XA_STATE(xas, &mapping->i_pages, *start);
+ struct page *page;
unsigned ret = 0;
if (unlikely(!nr_pages))
return 0;
rcu_read_lock();
- radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, *start) {
- struct page *head, *page;
-
- if (iter.index > end)
- break;
-repeat:
- page = radix_tree_deref_slot(slot);
- if (unlikely(!page))
+ xas_for_each(&xas, page, end) {
+ struct page *head;
+ if (xas_retry(&xas, page))
continue;
-
- if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
- continue;
- }
- /*
- * A shadow entry of a recently evicted page,
- * or a swap entry from shmem/tmpfs. Skip
- * over it.
- */
+ /* Skip over shadow, swap and DAX entries */
+ if (xa_is_value(page))
continue;
- }
head = compound_head(page);
if (!page_cache_get_speculative(head))
- goto repeat;
+ goto retry;
/* The page was split under us? */
- if (compound_head(page) != head) {
- put_page(head);
- goto repeat;
- }
+ if (compound_head(page) != head)
+ goto put_page;
/* Has the page moved? */
- if (unlikely(page != *slot)) {
- put_page(head);
- goto repeat;
- }
+ if (unlikely(page != xas_reload(&xas)))
+ goto put_page;
pages[ret] = page;
if (++ret == nr_pages) {
- *start = pages[ret - 1]->index + 1;
+ *start = page->index + 1;
goto out;
}
+ continue;
+put_page:
+ put_page(head);
+retry:
+ xas_reset(&xas);
}
/*
* We come here when there is no page beyond @end. We take care to not
* overflow the index @start as it confuses some of the callers. This
- * breaks the iteration when there is page at index -1 but that is
+ * breaks the iteration when there is a page at index -1 but that is
* already broken anyway.
*/
if (end == (pgoff_t)-1)
@@ -1802,57 +1745,43 @@ out:
unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
unsigned int nr_pages, struct page **pages)
{
- struct radix_tree_iter iter;
- void **slot;
+ XA_STATE(xas, &mapping->i_pages, index);
+ struct page *page;
unsigned int ret = 0;
if (unlikely(!nr_pages))
return 0;
rcu_read_lock();
- radix_tree_for_each_contig(slot, &mapping->i_pages, &iter, index) {
- struct page *head, *page;
-repeat:
- page = radix_tree_deref_slot(slot);
- /* The hole, there no reason to continue */
- if (unlikely(!page))
- break;
-
- if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
- continue;
- }
- /*
- * A shadow entry of a recently evicted page,
- * or a swap entry from shmem/tmpfs. Stop
- * looking for contiguous pages.
- */
+ for (page = xas_load(&xas); page; page = xas_next(&xas)) {
+ struct page *head;
+ if (xas_retry(&xas, page))
+ continue;
+ /*
+ * If the entry has been swapped out, we can stop looking.
+ * No current caller is looking for DAX entries.
+ */
+ if (xa_is_value(page))
break;
- }
head = compound_head(page);
if (!page_cache_get_speculative(head))
- goto repeat;
+ goto retry;
/* The page was split under us? */
- if (compound_head(page) != head) {
- put_page(head);
- goto repeat;
- }
+ if (compound_head(page) != head)
+ goto put_page;
/* Has the page moved? */
- if (unlikely(page != *slot)) {
- put_page(head);
- goto repeat;
- }
+ if (unlikely(page != xas_reload(&xas)))
+ goto put_page;
/*
* must check mapping and index after taking the ref.
* otherwise we can get both false positives and false
* negatives, which is just confusing to the caller.
*/
- if (page->mapping == NULL || page_to_pgoff(page) != iter.index) {
+ if (!page->mapping || page_to_pgoff(page) != xas.xa_index) {
put_page(page);
break;
}
@@ -1860,6 +1789,11 @@ repeat:
pages[ret] = page;
if (++ret == nr_pages)
break;
+ continue;
+put_page:
+ put_page(head);
+retry:
+ xas_reset(&xas);
}
rcu_read_unlock();
return ret;
@@ -1879,74 +1813,58 @@ EXPORT_SYMBOL(find_get_pages_contig);
* @tag. We update @index to index the next page for the traversal.
*/
unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
- pgoff_t end, int tag, unsigned int nr_pages,
+ pgoff_t end, xa_mark_t tag, unsigned int nr_pages,
struct page **pages)
{
- struct radix_tree_iter iter;
- void **slot;
+ XA_STATE(xas, &mapping->i_pages, *index);
+ struct page *page;
unsigned ret = 0;
if (unlikely(!nr_pages))
return 0;
rcu_read_lock();
- radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, *index, tag) {
- struct page *head, *page;
-
- if (iter.index > end)
- break;
-repeat:
- page = radix_tree_deref_slot(slot);
- if (unlikely(!page))
+ xas_for_each_marked(&xas, page, end, tag) {
+ struct page *head;
+ if (xas_retry(&xas, page))
continue;
-
- if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
- continue;
- }
- /*
- * A shadow entry of a recently evicted page.
- *
- * Those entries should never be tagged, but
- * this tree walk is lockless and the tags are
- * looked up in bulk, one radix tree node at a
- * time, so there is a sizable window for page
- * reclaim to evict a page we saw tagged.
- *
- * Skip over it.
- */
+ /*
+ * Shadow entries should never be tagged, but this iteration
+ * is lockless so there is a window for page reclaim to evict
+ * a page we saw tagged. Skip over it.
+ */
+ if (xa_is_value(page))
continue;
- }
head = compound_head(page);
if (!page_cache_get_speculative(head))
- goto repeat;
+ goto retry;
/* The page was split under us? */
- if (compound_head(page) != head) {
- put_page(head);
- goto repeat;
- }
+ if (compound_head(page) != head)
+ goto put_page;
/* Has the page moved? */
- if (unlikely(page != *slot)) {
- put_page(head);
- goto repeat;
- }
+ if (unlikely(page != xas_reload(&xas)))
+ goto put_page;
pages[ret] = page;
if (++ret == nr_pages) {
- *index = pages[ret - 1]->index + 1;
+ *index = page->index + 1;
goto out;
}
+ continue;
+put_page:
+ put_page(head);
+retry:
+ xas_reset(&xas);
}
/*
- * We come here when we got at @end. We take care to not overflow the
+ * We come here when we got to @end. We take care to not overflow the
* index @index as it confuses some of the callers. This breaks the
- * iteration when there is page at index -1 but that is already broken
- * anyway.
+ * iteration when there is a page at index -1 but that is already
+ * broken anyway.
*/
if (end == (pgoff_t)-1)
*index = (pgoff_t)-1;
@@ -1972,57 +1890,51 @@ EXPORT_SYMBOL(find_get_pages_range_tag);
* @tag.
*/
unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start,
- int tag, unsigned int nr_entries,
+ xa_mark_t tag, unsigned int nr_entries,
struct page **entries, pgoff_t *indices)
{
- void **slot;
+ XA_STATE(xas, &mapping->i_pages, start);
+ struct page *page;
unsigned int ret = 0;
- struct radix_tree_iter iter;
if (!nr_entries)
return 0;
rcu_read_lock();
- radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, start, tag) {
- struct page *head, *page;
-repeat:
- page = radix_tree_deref_slot(slot);
- if (unlikely(!page))
+ xas_for_each_marked(&xas, page, ULONG_MAX, tag) {
+ struct page *head;
+ if (xas_retry(&xas, page))
continue;
- if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
- continue;
- }
-
- /*
- * A shadow entry of a recently evicted page, a swap
- * entry from shmem/tmpfs or a DAX entry. Return it
- * without attempting to raise page count.
- */
+ /*
+ * A shadow entry of a recently evicted page, a swap
+ * entry from shmem/tmpfs or a DAX entry. Return it
+ * without attempting to raise page count.
+ */
+ if (xa_is_value(page))
goto export;
- }
head = compound_head(page);
if (!page_cache_get_speculative(head))
- goto repeat;
+ goto retry;
/* The page was split under us? */
- if (compound_head(page) != head) {
- put_page(head);
- goto repeat;
- }
+ if (compound_head(page) != head)
+ goto put_page;
/* Has the page moved? */
- if (unlikely(page != *slot)) {
- put_page(head);
- goto repeat;
- }
+ if (unlikely(page != xas_reload(&xas)))
+ goto put_page;
+
export:
- indices[ret] = iter.index;
+ indices[ret] = xas.xa_index;
entries[ret] = page;
if (++ret == nr_entries)
break;
+ continue;
+put_page:
+ put_page(head);
+retry:
+ xas_reset(&xas);
}
rcu_read_unlock();
return ret;
@@ -2626,45 +2538,31 @@ EXPORT_SYMBOL(filemap_fault);
void filemap_map_pages(struct vm_fault *vmf,
pgoff_t start_pgoff, pgoff_t end_pgoff)
{
- struct radix_tree_iter iter;
- void **slot;
struct file *file = vmf->vma->vm_file;
struct address_space *mapping = file->f_mapping;
pgoff_t last_pgoff = start_pgoff;
unsigned long max_idx;
+ XA_STATE(xas, &mapping->i_pages, start_pgoff);
struct page *head, *page;
rcu_read_lock();
- radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start_pgoff) {
- if (iter.index > end_pgoff)
- break;
-repeat:
- page = radix_tree_deref_slot(slot);
- if (unlikely(!page))
- goto next;
- if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
- continue;
- }
+ xas_for_each(&xas, page, end_pgoff) {
+ if (xas_retry(&xas, page))
+ continue;
+ if (xa_is_value(page))
goto next;
- }
head = compound_head(page);
if (!page_cache_get_speculative(head))
- goto repeat;
+ goto next;
/* The page was split under us? */
- if (compound_head(page) != head) {
- put_page(head);
- goto repeat;
- }
+ if (compound_head(page) != head)
+ goto skip;
/* Has the page moved? */
- if (unlikely(page != *slot)) {
- put_page(head);
- goto repeat;
- }
+ if (unlikely(page != xas_reload(&xas)))
+ goto skip;
if (!PageUptodate(page) ||
PageReadahead(page) ||
@@ -2683,10 +2581,10 @@ repeat:
if (file->f_ra.mmap_miss > 0)
file->f_ra.mmap_miss--;
- vmf->address += (iter.index - last_pgoff) << PAGE_SHIFT;
+ vmf->address += (xas.xa_index - last_pgoff) << PAGE_SHIFT;
if (vmf->pte)
- vmf->pte += iter.index - last_pgoff;
- last_pgoff = iter.index;
+ vmf->pte += xas.xa_index - last_pgoff;
+ last_pgoff = xas.xa_index;
if (alloc_set_pte(vmf, NULL, page))
goto unlock;
unlock_page(page);
@@ -2699,8 +2597,6 @@ next:
/* Huge page is mapped? No need to proceed. */
if (pmd_trans_huge(*vmf->pmd))
break;
- if (iter.index == end_pgoff)
- break;
}
rcu_read_unlock();
}
@@ -2810,7 +2706,7 @@ repeat:
put_page(page);
if (err == -EEXIST)
goto repeat;
- /* Presumably ENOMEM for radix tree node */
+ /* Presumably ENOMEM for xarray node */
return ERR_PTR(err);
}
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 25ef59b7ee34..4e4ef8fa479d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2450,13 +2450,13 @@ static void __split_huge_page(struct page *page, struct list_head *list,
ClearPageCompound(head);
/* See comment in __split_huge_page_tail() */
if (PageAnon(head)) {
- /* Additional pin to radix tree of swap cache */
+ /* Additional pin to swap cache */
if (PageSwapCache(head))
page_ref_add(head, 2);
else
page_ref_inc(head);
} else {
- /* Additional pin to radix tree */
+ /* Additional pin to page cache */
page_ref_add(head, 2);
xa_unlock(&head->mapping->i_pages);
}
@@ -2568,7 +2568,7 @@ bool can_split_huge_page(struct page *page, int *pextra_pins)
{
int extra_pins;
- /* Additional pins from radix tree */
+ /* Additional pins from page cache */
if (PageAnon(page))
extra_pins = PageSwapCache(page) ? HPAGE_PMD_NR : 0;
else
@@ -2664,17 +2664,14 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
spin_lock_irqsave(zone_lru_lock(page_zone(head)), flags);
if (mapping) {
- void **pslot;
+ XA_STATE(xas, &mapping->i_pages, page_index(head));
- xa_lock(&mapping->i_pages);
- pslot = radix_tree_lookup_slot(&mapping->i_pages,
- page_index(head));
/*
- * Check if the head page is present in radix tree.
+ * Check if the head page is present in page cache.
* We assume all tail are present too, if head is there.
*/
- if (radix_tree_deref_slot_protected(pslot,
- &mapping->i_pages.xa_lock) != head)
+ xa_lock(&mapping->i_pages);
+ if (xas_load(&xas) != head)
goto fail;
}
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index a31d740e6cd1..c13625c1ad5e 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1288,17 +1288,17 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
*
* Basic scheme is simple, details are more complex:
* - allocate and freeze a new huge page;
- * - scan over radix tree replacing old pages the new one
+ * - scan page cache replacing old pages with the new one
* + swap in pages if necessary;
* + fill in gaps;
- * + keep old pages around in case if rollback is required;
- * - if replacing succeed:
+ * + keep old pages around in case rollback is required;
+ * - if replacing succeeds:
* + copy data over;
* + free old pages;
* + unfreeze huge page;
* - if replacing failed;
* + put all pages back and unfreeze them;
- * + restore gaps in the radix-tree;
+ * + restore gaps in the page cache;
* + free huge page;
*/
static void collapse_shmem(struct mm_struct *mm,
@@ -1306,12 +1306,11 @@ static void collapse_shmem(struct mm_struct *mm,
struct page **hpage, int node)
{
gfp_t gfp;
- struct page *page, *new_page, *tmp;
+ struct page *new_page;
struct mem_cgroup *memcg;
pgoff_t index, end = start + HPAGE_PMD_NR;
LIST_HEAD(pagelist);
- struct radix_tree_iter iter;
- void **slot;
+ XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER);
int nr_none = 0, result = SCAN_SUCCEED;
VM_BUG_ON(start & (HPAGE_PMD_NR - 1));
@@ -1336,48 +1335,49 @@ static void collapse_shmem(struct mm_struct *mm,
__SetPageLocked(new_page);
BUG_ON(!page_ref_freeze(new_page, 1));
-
/*
- * At this point the new_page is 'frozen' (page_count() is zero), locked
- * and not up-to-date. It's safe to insert it into radix tree, because
- * nobody would be able to map it or use it in other way until we
- * unfreeze it.
+ * At this point the new_page is 'frozen' (page_count() is zero),
+ * locked and not up-to-date. It's safe to insert it into the page
+ * cache, because nobody would be able to map it or use it in other
+ * way until we unfreeze it.
*/
- index = start;
- xa_lock_irq(&mapping->i_pages);
- radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
- int n = min(iter.index, end) - index;
-
- /*
- * Handle holes in the radix tree: charge it from shmem and
- * insert relevant subpage of new_page into the radix-tree.
- */
- if (n && !shmem_charge(mapping->host, n)) {
- result = SCAN_FAIL;
+ /* This will be less messy when we use multi-index entries */
+ do {
+ xas_lock_irq(&xas);
+ xas_create_range(&xas);
+ if (!xas_error(&xas))
break;
- }
- nr_none += n;
- for (; index < min(iter.index, end); index++) {
- radix_tree_insert(&mapping->i_pages, index,
- new_page + (index % HPAGE_PMD_NR));
- }
+ xas_unlock_irq(&xas);
+ if (!xas_nomem(&xas, GFP_KERNEL))
+ goto out;
+ } while (1);
- /* We are done. */
- if (index >= end)
- break;
+ xas_set(&xas, start);
+ for (index = start; index < end; index++) {
+ struct page *page = xas_next(&xas);
+
+ VM_BUG_ON(index != xas.xa_index);
+ if (!page) {
+ if (!shmem_charge(mapping->host, 1)) {
+ result = SCAN_FAIL;
+ break;
+ }
+ xas_store(&xas, new_page + (index % HPAGE_PMD_NR));
+ nr_none++;
+ continue;
+ }
- page = radix_tree_deref_slot_protected(slot,
- &mapping->i_pages.xa_lock);
- if (radix_tree_exceptional_entry(page) || !PageUptodate(page)) {
- xa_unlock_irq(&mapping->i_pages);
+ if (xa_is_value(page) || !PageUptodate(page)) {
+ xas_unlock_irq(&xas);
/* swap in or instantiate fallocated page */
if (shmem_getpage(mapping->host, index, &page,
SGP_NOHUGE)) {
result = SCAN_FAIL;
- goto tree_unlocked;
+ goto xa_unlocked;
}
- xa_lock_irq(&mapping->i_pages);
+ xas_lock_irq(&xas);
+ xas_set(&xas, index);
} else if (trylock_page(page)) {
get_page(page);
} else {
@@ -1397,7 +1397,7 @@ static void collapse_shmem(struct mm_struct *mm,
result = SCAN_TRUNCATED;
goto out_unlock;
}
- xa_unlock_irq(&mapping->i_pages);
+ xas_unlock_irq(&xas);
if (isolate_lru_page(page)) {
result = SCAN_DEL_PAGE_LRU;
@@ -1407,17 +1407,16 @@ static void collapse_shmem(struct mm_struct *mm,
if (page_mapped(page))
unmap_mapping_pages(mapping, index, 1, false);
- xa_lock_irq(&mapping->i_pages);
+ xas_lock_irq(&xas);
+ xas_set(&xas, index);
- slot = radix_tree_lookup_slot(&mapping->i_pages, index);
- VM_BUG_ON_PAGE(page != radix_tree_deref_slot_protected(slot,
- &mapping->i_pages.xa_lock), page);
+ VM_BUG_ON_PAGE(page != xas_load(&xas), page);
VM_BUG_ON_PAGE(page_mapped(page), page);
/*
* The page is expected to have page_count() == 3:
* - we hold a pin on it;
- * - one reference from radix tree;
+ * - one reference from page cache;
* - one from isolate_lru_page;
*/
if (!page_ref_freeze(page, 3)) {
@@ -1432,56 +1431,30 @@ static void collapse_shmem(struct mm_struct *mm,
list_add_tail(&page->lru, &pagelist);
/* Finally, replace with the new page. */
- radix_tree_replace_slot(&mapping->i_pages, slot,
- new_page + (index % HPAGE_PMD_NR));
-
- slot = radix_tree_iter_resume(slot, &iter);
- index++;
+ xas_store(&xas, new_page + (index % HPAGE_PMD_NR));
continue;
out_lru:
- xa_unlock_irq(&mapping->i_pages);
+ xas_unlock_irq(&xas);
putback_lru_page(page);
out_isolate_failed:
unlock_page(page);
put_page(page);
- goto tree_unlocked;
+ goto xa_unlocked;
out_unlock:
unlock_page(page);
put_page(page);
break;
}
+ xas_unlock_irq(&xas);
- /*
- * Handle hole in radix tree at the end of the range.
- * This code only triggers if there's nothing in radix tree
- * beyond 'end'.
- */
- if (result == SCAN_SUCCEED && index < end) {
- int n = end - index;
-
- if (!shmem_charge(mapping->host, n)) {
- result = SCAN_FAIL;
- goto tree_locked;
- }
-
- for (; index < end; index++) {
- radix_tree_insert(&mapping->i_pages, index,
- new_page + (index % HPAGE_PMD_NR));
- }
- nr_none += n;
- }
-
-tree_locked:
- xa_unlock_irq(&mapping->i_pages);
-tree_unlocked:
-
+xa_unlocked:
if (result == SCAN_SUCCEED) {
- unsigned long flags;
+ struct page *page, *tmp;
struct zone *zone = page_zone(new_page);
/*
- * Replacing old pages with new one has succeed, now we need to
- * copy the content and free old pages.
+ * Replacing old pages with new one has succeeded, now we
+ * need to copy the content and free the old pages.
*/
list_for_each_entry_safe(page, tmp, &pagelist, lru) {
copy_highpage(new_page + (page->index % HPAGE_PMD_NR),
@@ -1495,16 +1468,16 @@ tree_unlocked:
put_page(page);
}
- local_irq_save(flags);
+ local_irq_disable();
__inc_node_page_state(new_page, NR_SHMEM_THPS);
if (nr_none) {
__mod_node_page_state(zone->zone_pgdat, NR_FILE_PAGES, nr_none);
__mod_node_page_state(zone->zone_pgdat, NR_SHMEM, nr_none);
}
- local_irq_restore(flags);
+ local_irq_enable();
/*
- * Remove pte page tables, so we can re-faulti
+ * Remove pte page tables, so we can re-fault
* the page as huge.
*/
retract_page_tables(mapping, start);
@@ -1521,37 +1494,37 @@ tree_unlocked:
khugepaged_pages_collapsed++;
} else {
- /* Something went wrong: rollback changes to the radix-tree */
+ struct page *page;
+ /* Something went wrong: roll back page cache changes */
shmem_uncharge(mapping->host, nr_none);
- xa_lock_irq(&mapping->i_pages);
- radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
- if (iter.index >= end)
- break;
+ xas_lock_irq(&xas);
+ xas_set(&xas, start);
+ xas_for_each(&xas, page, end - 1) {
page = list_first_entry_or_null(&pagelist,
struct page, lru);
- if (!page || iter.index < page->index) {
+ if (!page || xas.xa_index < page->index) {
if (!nr_none)
break;
nr_none--;
/* Put holes back where they were */
- radix_tree_delete(&mapping->i_pages, iter.index);
+ xas_store(&xas, NULL);
continue;
}
- VM_BUG_ON_PAGE(page->index != iter.index, page);
+ VM_BUG_ON_PAGE(page->index != xas.xa_index, page);
/* Unfreeze the page. */
list_del(&page->lru);
page_ref_unfreeze(page, 2);
- radix_tree_replace_slot(&mapping->i_pages, slot, page);
- slot = radix_tree_iter_resume(slot, &iter);
- xa_unlock_irq(&mapping->i_pages);
+ xas_store(&xas, page);
+ xas_pause(&xas);
+ xas_unlock_irq(&xas);
putback_lru_page(page);
unlock_page(page);
- xa_lock_irq(&mapping->i_pages);
+ xas_lock_irq(&xas);
}
VM_BUG_ON(nr_none);
- xa_unlock_irq(&mapping->i_pages);
+ xas_unlock_irq(&xas);
/* Unfreeze new_page, caller would take care about freeing it */
page_ref_unfreeze(new_page, 1);
@@ -1569,8 +1542,7 @@ static void khugepaged_scan_shmem(struct mm_struct *mm,
pgoff_t start, struct page **hpage)
{
struct page *page = NULL;
- struct radix_tree_iter iter;
- void **slot;
+ XA_STATE(xas, &mapping->i_pages, start);
int present, swap;
int node = NUMA_NO_NODE;
int result = SCAN_SUCCEED;
@@ -1579,17 +1551,11 @@ static void khugepaged_scan_shmem(struct mm_struct *mm,
swap = 0;
memset(khugepaged_node_load, 0, sizeof(khugepaged_node_load));
rcu_read_lock();
- radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
- if (iter.index >= start + HPAGE_PMD_NR)
- break;
-
- page = radix_tree_deref_slot(slot);
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
+ xas_for_each(&xas, page, start + HPAGE_PMD_NR - 1) {
+ if (xas_retry(&xas, page))
continue;
- }
- if (radix_tree_exception(page)) {
+ if (xa_is_value(page)) {
if (++swap > khugepaged_max_ptes_swap) {
result = SCAN_EXCEED_SWAP_PTE;
break;
@@ -1628,7 +1594,7 @@ static void khugepaged_scan_shmem(struct mm_struct *mm,
present++;
if (need_resched()) {
- slot = radix_tree_iter_resume(slot, &iter);
+ xas_pause(&xas);
cond_resched_rcu();
}
}
diff --git a/mm/madvise.c b/mm/madvise.c
index 71d21df2a3f3..6cb1ca93e290 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -251,7 +251,7 @@ static void force_shm_swapin_readahead(struct vm_area_struct *vma,
index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
page = find_get_entry(mapping, index);
- if (!radix_tree_exceptional_entry(page)) {
+ if (!xa_is_value(page)) {
if (page)
put_page(page);
continue;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 10a9b554d69f..54920cbc46bf 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4728,7 +4728,7 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
/* shmem/tmpfs may report page out on swap: account for that too. */
if (shmem_mapping(mapping)) {
page = find_get_entry(mapping, pgoff);
- if (radix_tree_exceptional_entry(page)) {
+ if (xa_is_value(page)) {
swp_entry_t swp = radix_to_swp_entry(page);
if (do_memsw_account())
*entry = swp;
diff --git a/mm/memfd.c b/mm/memfd.c
index 2bb5e257080e..97264c79d2cd 100644
--- a/mm/memfd.c
+++ b/mm/memfd.c
@@ -21,44 +21,36 @@
#include <uapi/linux/memfd.h>
/*
- * We need a tag: a new tag would expand every radix_tree_node by 8 bytes,
+ * We need a tag: a new tag would expand every xa_node by 8 bytes,
* so reuse a tag which we firmly believe is never set or cleared on tmpfs
* or hugetlbfs because they are memory only filesystems.
*/
#define MEMFD_TAG_PINNED PAGECACHE_TAG_TOWRITE
#define LAST_SCAN 4 /* about 150ms max */
-static void memfd_tag_pins(struct address_space *mapping)
+static void memfd_tag_pins(struct xa_state *xas)
{
- struct radix_tree_iter iter;
- void __rcu **slot;
- pgoff_t start;
struct page *page;
+ unsigned int tagged = 0;
lru_add_drain();
- start = 0;
- rcu_read_lock();
-
- radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
- page = radix_tree_deref_slot(slot);
- if (!page || radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
- continue;
- }
- } else if (page_count(page) - page_mapcount(page) > 1) {
- xa_lock_irq(&mapping->i_pages);
- radix_tree_tag_set(&mapping->i_pages, iter.index,
- MEMFD_TAG_PINNED);
- xa_unlock_irq(&mapping->i_pages);
- }
- if (need_resched()) {
- slot = radix_tree_iter_resume(slot, &iter);
- cond_resched_rcu();
- }
+ xas_lock_irq(xas);
+ xas_for_each(xas, page, ULONG_MAX) {
+ if (xa_is_value(page))
+ continue;
+ if (page_count(page) - page_mapcount(page) > 1)
+ xas_set_mark(xas, MEMFD_TAG_PINNED);
+
+ if (++tagged % XA_CHECK_SCHED)
+ continue;
+
+ xas_pause(xas);
+ xas_unlock_irq(xas);
+ cond_resched();
+ xas_lock_irq(xas);
}
- rcu_read_unlock();
+ xas_unlock_irq(xas);
}
/*
@@ -72,17 +64,17 @@ static void memfd_tag_pins(struct address_space *mapping)
*/
static int memfd_wait_for_pins(struct address_space *mapping)
{
- struct radix_tree_iter iter;
- void __rcu **slot;
- pgoff_t start;
+ XA_STATE(xas, &mapping->i_pages, 0);
struct page *page;
int error, scan;
- memfd_tag_pins(mapping);
+ memfd_tag_pins(&xas);
error = 0;
for (scan = 0; scan <= LAST_SCAN; scan++) {
- if (!radix_tree_tagged(&mapping->i_pages, MEMFD_TAG_PINNED))
+ unsigned int tagged = 0;
+
+ if (!xas_marked(&xas, MEMFD_TAG_PINNED))
break;
if (!scan)
@@ -90,45 +82,34 @@ static int memfd_wait_for_pins(struct address_space *mapping)
else if (schedule_timeout_killable((HZ << scan) / 200))
scan = LAST_SCAN;
- start = 0;
- rcu_read_lock();
- radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter,
- start, MEMFD_TAG_PINNED) {
-
- page = radix_tree_deref_slot(slot);
- if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
- continue;
- }
-
- page = NULL;
- }
-
- if (page &&
- page_count(page) - page_mapcount(page) != 1) {
- if (scan < LAST_SCAN)
- goto continue_resched;
-
+ xas_set(&xas, 0);
+ xas_lock_irq(&xas);
+ xas_for_each_marked(&xas, page, ULONG_MAX, MEMFD_TAG_PINNED) {
+ bool clear = true;
+ if (xa_is_value(page))
+ continue;
+ if (page_count(page) - page_mapcount(page) != 1) {
/*
* On the last scan, we clean up all those tags
* we inserted; but make a note that we still
* found pages pinned.
*/
- error = -EBUSY;
+ if (scan == LAST_SCAN)
+ error = -EBUSY;
+ else
+ clear = false;
}
+ if (clear)
+ xas_clear_mark(&xas, MEMFD_TAG_PINNED);
+ if (++tagged % XA_CHECK_SCHED)
+ continue;
- xa_lock_irq(&mapping->i_pages);
- radix_tree_tag_clear(&mapping->i_pages,
- iter.index, MEMFD_TAG_PINNED);
- xa_unlock_irq(&mapping->i_pages);
-continue_resched:
- if (need_resched()) {
- slot = radix_tree_iter_resume(slot, &iter);
- cond_resched_rcu();
- }
+ xas_pause(&xas);
+ xas_unlock_irq(&xas);
+ cond_resched();
+ xas_lock_irq(&xas);
}
- rcu_read_unlock();
+ xas_unlock_irq(&xas);
}
return error;
diff --git a/mm/migrate.c b/mm/migrate.c
index b6700f2962f3..f7e4bfdc13b7 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -326,7 +326,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
page = migration_entry_to_page(entry);
/*
- * Once radix-tree replacement of page migration started, page_count
+ * Once page cache replacement of page migration started, page_count
* *must* be zero. And, we don't want to call wait_on_page_locked()
* against a page without get_page().
* So, we use get_page_unless_zero(), here. Even failed, page fault
@@ -441,10 +441,10 @@ int migrate_page_move_mapping(struct address_space *mapping,
struct buffer_head *head, enum migrate_mode mode,
int extra_count)
{
+ XA_STATE(xas, &mapping->i_pages, page_index(page));
struct zone *oldzone, *newzone;
int dirty;
int expected_count = 1 + extra_count;
- void **pslot;
/*
* Device public or private pages have an extra refcount as they are
@@ -470,21 +470,16 @@ int migrate_page_move_mapping(struct address_space *mapping,
oldzone = page_zone(page);
newzone = page_zone(newpage);
- xa_lock_irq(&mapping->i_pages);
-
- pslot = radix_tree_lookup_slot(&mapping->i_pages,
- page_index(page));
+ xas_lock_irq(&xas);
expected_count += hpage_nr_pages(page) + page_has_private(page);
- if (page_count(page) != expected_count ||
- radix_tree_deref_slot_protected(pslot,
- &mapping->i_pages.xa_lock) != page) {
- xa_unlock_irq(&mapping->i_pages);
+ if (page_count(page) != expected_count || xas_load(&xas) != page) {
+ xas_unlock_irq(&xas);
return -EAGAIN;
}
if (!page_ref_freeze(page, expected_count)) {
- xa_unlock_irq(&mapping->i_pages);
+ xas_unlock_irq(&xas);
return -EAGAIN;
}
@@ -498,7 +493,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
if (mode == MIGRATE_ASYNC && head &&
!buffer_migrate_lock_buffers(head, mode)) {
page_ref_unfreeze(page, expected_count);
- xa_unlock_irq(&mapping->i_pages);
+ xas_unlock_irq(&xas);
return -EAGAIN;
}
@@ -526,16 +521,13 @@ int migrate_page_move_mapping(struct address_space *mapping,
SetPageDirty(newpage);
}
- radix_tree_replace_slot(&mapping->i_pages, pslot, newpage);
+ xas_store(&xas, newpage);
if (PageTransHuge(page)) {
int i;
- int index = page_index(page);
for (i = 1; i < HPAGE_PMD_NR; i++) {
- pslot = radix_tree_lookup_slot(&mapping->i_pages,
- index + i);
- radix_tree_replace_slot(&mapping->i_pages, pslot,
- newpage + i);
+ xas_next(&xas);
+ xas_store(&xas, newpage + i);
}
}
@@ -546,7 +538,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
*/
page_ref_unfreeze(page, expected_count - hpage_nr_pages(page));
- xa_unlock(&mapping->i_pages);
+ xas_unlock(&xas);
/* Leave irq disabled to prevent preemption while updating stats */
/*
@@ -586,22 +578,18 @@ EXPORT_SYMBOL(migrate_page_move_mapping);
int migrate_huge_page_move_mapping(struct address_space *mapping,
struct page *newpage, struct page *page)
{
+ XA_STATE(xas, &mapping->i_pages, page_index(page));
int expected_count;
- void **pslot;
-
- xa_lock_irq(&mapping->i_pages);
-
- pslot = radix_tree_lookup_slot(&mapping->i_pages, page_index(page));
+ xas_lock_irq(&xas);
expected_count = 2 + page_has_private(page);
- if (page_count(page) != expected_count ||
- radix_tree_deref_slot_protected(pslot, &mapping->i_pages.xa_lock) != page) {
- xa_unlock_irq(&mapping->i_pages);
+ if (page_count(page) != expected_count || xas_load(&xas) != page) {
+ xas_unlock_irq(&xas);
return -EAGAIN;
}
if (!page_ref_freeze(page, expected_count)) {
- xa_unlock_irq(&mapping->i_pages);
+ xas_unlock_irq(&xas);
return -EAGAIN;
}
@@ -610,11 +598,11 @@ int migrate_huge_page_move_mapping(struct address_space *mapping,
get_page(newpage);
- radix_tree_replace_slot(&mapping->i_pages, pslot, newpage);
+ xas_store(&xas, newpage);
page_ref_unfreeze(page, expected_count - 1);
- xa_unlock_irq(&mapping->i_pages);
+ xas_unlock_irq(&xas);
return MIGRATEPAGE_SUCCESS;
}
diff --git a/mm/mincore.c b/mm/mincore.c
index fc37afe226e6..4985965aa20a 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -66,7 +66,7 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff)
* shmem/tmpfs may return swap: account for swapcache
* page too.
*/
- if (radix_tree_exceptional_entry(page)) {
+ if (xa_is_value(page)) {
swp_entry_t swp = radix_to_swp_entry(page);
page = find_get_page(swap_address_space(swp),
swp_offset(swp));
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 439a304a6c92..3f690bae6b78 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2097,34 +2097,25 @@ void __init page_writeback_init(void)
* dirty pages in the file (thus it is important for this function to be quick
* so that it can tag pages faster than a dirtying process can create them).
*/
-/*
- * We tag pages in batches of WRITEBACK_TAG_BATCH to reduce the i_pages lock
- * latency.
- */
void tag_pages_for_writeback(struct address_space *mapping,
pgoff_t start, pgoff_t end)
{
-#define WRITEBACK_TAG_BATCH 4096
- unsigned long tagged = 0;
- struct radix_tree_iter iter;
- void **slot;
+ XA_STATE(xas, &mapping->i_pages, start);
+ unsigned int tagged = 0;
+ void *page;
- xa_lock_irq(&mapping->i_pages);
- radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, start,
- PAGECACHE_TAG_DIRTY) {
- if (iter.index > end)
- break;
- radix_tree_iter_tag_set(&mapping->i_pages, &iter,
- PAGECACHE_TAG_TOWRITE);
- tagged++;
- if ((tagged % WRITEBACK_TAG_BATCH) != 0)
+ xas_lock_irq(&xas);
+ xas_for_each_marked(&xas, page, end, PAGECACHE_TAG_DIRTY) {
+ xas_set_mark(&xas, PAGECACHE_TAG_TOWRITE);
+ if (++tagged % XA_CHECK_SCHED)
continue;
- slot = radix_tree_iter_resume(slot, &iter);
- xa_unlock_irq(&mapping->i_pages);
+
+ xas_pause(&xas);
+ xas_unlock_irq(&xas);
cond_resched();
- xa_lock_irq(&mapping->i_pages);
+ xas_lock_irq(&xas);
}
- xa_unlock_irq(&mapping->i_pages);
+ xas_unlock_irq(&xas);
}
EXPORT_SYMBOL(tag_pages_for_writeback);
@@ -2170,7 +2161,7 @@ int write_cache_pages(struct address_space *mapping,
pgoff_t end; /* Inclusive */
pgoff_t done_index;
int range_whole = 0;
- int tag;
+ xa_mark_t tag;
pagevec_init(&pvec);
if (wbc->range_cyclic) {
@@ -2442,7 +2433,7 @@ void account_page_cleaned(struct page *page, struct address_space *mapping,
/*
* For address_spaces which do not use buffers. Just tag the page as dirty in
- * its radix tree.
+ * the xarray.
*
* This is also used when a single buffer is being dirtied: we want to set the
* page dirty in that case, but not all the buffers. This is a "bottom-up"
@@ -2468,7 +2459,7 @@ int __set_page_dirty_nobuffers(struct page *page)
BUG_ON(page_mapping(page) != mapping);
WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
account_page_dirtied(page, mapping);
- radix_tree_tag_set(&mapping->i_pages, page_index(page),
+ __xa_set_mark(&mapping->i_pages, page_index(page),
PAGECACHE_TAG_DIRTY);
xa_unlock_irqrestore(&mapping->i_pages, flags);
unlock_page_memcg(page);
@@ -2631,13 +2622,13 @@ EXPORT_SYMBOL(__cancel_dirty_page);
* Returns true if the page was previously dirty.
*
* This is for preparing to put the page under writeout. We leave the page
- * tagged as dirty in the radix tree so that a concurrent write-for-sync
+ * tagged as dirty in the xarray so that a concurrent write-for-sync
* can discover it via a PAGECACHE_TAG_DIRTY walk. The ->writepage
* implementation will run either set_page_writeback() or set_page_dirty(),
- * at which stage we bring the page's dirty flag and radix-tree dirty tag
+ * at which stage we bring the page's dirty flag and xarray dirty tag
* back into sync.
*
- * This incoherency between the page's dirty flag and radix-tree tag is
+ * This incoherency between the page's dirty flag and xarray tag is
* unfortunate, but it only exists while the page is locked.
*/
int clear_page_dirty_for_io(struct page *page)
@@ -2718,7 +2709,7 @@ int test_clear_page_writeback(struct page *page)
xa_lock_irqsave(&mapping->i_pages, flags);
ret = TestClearPageWriteback(page);
if (ret) {
- radix_tree_tag_clear(&mapping->i_pages, page_index(page),
+ __xa_clear_mark(&mapping->i_pages, page_index(page),
PAGECACHE_TAG_WRITEBACK);
if (bdi_cap_account_writeback(bdi)) {
struct bdi_writeback *wb = inode_to_wb(inode);
@@ -2758,11 +2749,13 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
lock_page_memcg(page);
if (mapping && mapping_use_writeback_tags(mapping)) {
+ XA_STATE(xas, &mapping->i_pages, page_index(page));
struct inode *inode = mapping->host;
struct backing_dev_info *bdi = inode_to_bdi(inode);
unsigned long flags;
- xa_lock_irqsave(&mapping->i_pages, flags);
+ xas_lock_irqsave(&xas, flags);
+ xas_load(&xas);
ret = TestSetPageWriteback(page);
if (!ret) {
bool on_wblist;
@@ -2770,8 +2763,7 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
on_wblist = mapping_tagged(mapping,
PAGECACHE_TAG_WRITEBACK);
- radix_tree_tag_set(&mapping->i_pages, page_index(page),
- PAGECACHE_TAG_WRITEBACK);
+ xas_set_mark(&xas, PAGECACHE_TAG_WRITEBACK);
if (bdi_cap_account_writeback(bdi))
inc_wb_stat(inode_to_wb(inode), WB_WRITEBACK);
@@ -2784,12 +2776,10 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
sb_mark_inode_writeback(mapping->host);
}
if (!PageDirty(page))
- radix_tree_tag_clear(&mapping->i_pages, page_index(page),
- PAGECACHE_TAG_DIRTY);
+ xas_clear_mark(&xas, PAGECACHE_TAG_DIRTY);
if (!keep_write)
- radix_tree_tag_clear(&mapping->i_pages, page_index(page),
- PAGECACHE_TAG_TOWRITE);
- xa_unlock_irqrestore(&mapping->i_pages, flags);
+ xas_clear_mark(&xas, PAGECACHE_TAG_TOWRITE);
+ xas_unlock_irqrestore(&xas, flags);
} else {
ret = TestSetPageWriteback(page);
}
@@ -2803,16 +2793,6 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
}
EXPORT_SYMBOL(__test_set_page_writeback);
-/*
- * Return true if any of the pages in the mapping are marked with the
- * passed tag.
- */
-int mapping_tagged(struct address_space *mapping, int tag)
-{
- return radix_tree_tagged(&mapping->i_pages, tag);
-}
-EXPORT_SYMBOL(mapping_tagged);
-
/**
* wait_for_stable_page() - wait for writeback to finish, if necessary.
* @page: The page to wait on.
diff --git a/mm/readahead.c b/mm/readahead.c
index 4e630143a0ba..f3d6f9656a3c 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -176,10 +176,8 @@ unsigned int __do_page_cache_readahead(struct address_space *mapping,
if (page_offset > end_index)
break;
- rcu_read_lock();
- page = radix_tree_lookup(&mapping->i_pages, page_offset);
- rcu_read_unlock();
- if (page && !radix_tree_exceptional_entry(page)) {
+ page = xa_load(&mapping->i_pages, page_offset);
+ if (page && !xa_is_value(page)) {
/*
* Page already present? Kick off the current batch of
* contiguous pages before continuing with the next
@@ -336,7 +334,7 @@ static pgoff_t count_history_pages(struct address_space *mapping,
pgoff_t head;
rcu_read_lock();
- head = page_cache_prev_hole(mapping, offset - 1, max);
+ head = page_cache_prev_miss(mapping, offset - 1, max);
rcu_read_unlock();
return offset - 1 - head;
@@ -425,7 +423,7 @@ ondemand_readahead(struct address_space *mapping,
pgoff_t start;
rcu_read_lock();
- start = page_cache_next_hole(mapping, offset + 1, max_pages);
+ start = page_cache_next_miss(mapping, offset + 1, max_pages);
rcu_read_unlock();
if (!start || start - offset > max_pages)
diff --git a/mm/shmem.c b/mm/shmem.c
index 446942677cd4..56bf122e0bb4 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -322,24 +322,20 @@ void shmem_uncharge(struct inode *inode, long pages)
}
/*
- * Replace item expected in radix tree by a new item, while holding tree lock.
+ * Replace item expected in xarray by a new item, while holding xa_lock.
*/
-static int shmem_radix_tree_replace(struct address_space *mapping,
+static int shmem_replace_entry(struct address_space *mapping,
pgoff_t index, void *expected, void *replacement)
{
- struct radix_tree_node *node;
- void __rcu **pslot;
+ XA_STATE(xas, &mapping->i_pages, index);
void *item;
VM_BUG_ON(!expected);
VM_BUG_ON(!replacement);
- item = __radix_tree_lookup(&mapping->i_pages, index, &node, &pslot);
- if (!item)
- return -ENOENT;
+ item = xas_load(&xas);
if (item != expected)
return -ENOENT;
- __radix_tree_replace(&mapping->i_pages, node, pslot,
- replacement, NULL);
+ xas_store(&xas, replacement);
return 0;
}
@@ -353,12 +349,7 @@ static int shmem_radix_tree_replace(struct address_space *mapping,
static bool shmem_confirm_swap(struct address_space *mapping,
pgoff_t index, swp_entry_t swap)
{
- void *item;
-
- rcu_read_lock();
- item = radix_tree_lookup(&mapping->i_pages, index);
- rcu_read_unlock();
- return item == swp_to_radix_entry(swap);
+ return xa_load(&mapping->i_pages, index) == swp_to_radix_entry(swap);
}
/*
@@ -586,9 +577,11 @@ static inline bool is_huge_enabled(struct shmem_sb_info *sbinfo)
*/
static int shmem_add_to_page_cache(struct page *page,
struct address_space *mapping,
- pgoff_t index, void *expected)
+ pgoff_t index, void *expected, gfp_t gfp)
{
- int error, nr = hpage_nr_pages(page);
+ XA_STATE_ORDER(xas, &mapping->i_pages, index, compound_order(page));
+ unsigned long i = 0;
+ unsigned long nr = 1UL << compound_order(page);
VM_BUG_ON_PAGE(PageTail(page), page);
VM_BUG_ON_PAGE(index != round_down(index, nr), page);
@@ -600,47 +593,39 @@ static int shmem_add_to_page_cache(struct page *page,
page->mapping = mapping;
page->index = index;
- xa_lock_irq(&mapping->i_pages);
- if (PageTransHuge(page)) {
- void __rcu **results;
- pgoff_t idx;
- int i;
-
- error = 0;
- if (radix_tree_gang_lookup_slot(&mapping->i_pages,
- &results, &idx, index, 1) &&
- idx < index + HPAGE_PMD_NR) {
- error = -EEXIST;
+ do {
+ void *entry;
+ xas_lock_irq(&xas);
+ entry = xas_find_conflict(&xas);
+ if (entry != expected)
+ xas_set_err(&xas, -EEXIST);
+ xas_create_range(&xas);
+ if (xas_error(&xas))
+ goto unlock;
+next:
+ xas_store(&xas, page + i);
+ if (++i < nr) {
+ xas_next(&xas);
+ goto next;
}
-
- if (!error) {
- for (i = 0; i < HPAGE_PMD_NR; i++) {
- error = radix_tree_insert(&mapping->i_pages,
- index + i, page + i);
- VM_BUG_ON(error);
- }
+ if (PageTransHuge(page)) {
count_vm_event(THP_FILE_ALLOC);
+ __inc_node_page_state(page, NR_SHMEM_THPS);
}
- } else if (!expected) {
- error = radix_tree_insert(&mapping->i_pages, index, page);
- } else {
- error = shmem_radix_tree_replace(mapping, index, expected,
- page);
- }
-
- if (!error) {
mapping->nrpages += nr;
- if (PageTransHuge(page))
- __inc_node_page_state(page, NR_SHMEM_THPS);
__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
__mod_node_page_state(page_pgdat(page), NR_SHMEM, nr);
- xa_unlock_irq(&mapping->i_pages);
- } else {
+unlock:
+ xas_unlock_irq(&xas);
+ } while (xas_nomem(&xas, gfp));
+
+ if (xas_error(&xas)) {
page->mapping = NULL;
- xa_unlock_irq(&mapping->i_pages);
page_ref_sub(page, nr);
+ return xas_error(&xas);
}
- return error;
+
+ return 0;
}
/*
@@ -654,7 +639,7 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap)
VM_BUG_ON_PAGE(PageCompound(page), page);
xa_lock_irq(&mapping->i_pages);
- error = shmem_radix_tree_replace(mapping, page->index, page, radswap);
+ error = shmem_replace_entry(mapping, page->index, page, radswap);
page->mapping = NULL;
mapping->nrpages--;
__dec_node_page_state(page, NR_FILE_PAGES);
@@ -665,7 +650,7 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap)
}
/*
- * Remove swap entry from radix tree, free the swap and its page cache.
+ * Remove swap entry from page cache, free the swap and its page cache.
*/
static int shmem_free_swap(struct address_space *mapping,
pgoff_t index, void *radswap)
@@ -673,7 +658,7 @@ static int shmem_free_swap(struct address_space *mapping,
void *old;
xa_lock_irq(&mapping->i_pages);
- old = radix_tree_delete_item(&mapping->i_pages, index, radswap);
+ old = __xa_cmpxchg(&mapping->i_pages, index, radswap, NULL, 0);
xa_unlock_irq(&mapping->i_pages);
if (old != radswap)
return -ENOENT;
@@ -691,29 +676,19 @@ static int shmem_free_swap(struct address_space *mapping,
unsigned long shmem_partial_swap_usage(struct address_space *mapping,
pgoff_t start, pgoff_t end)
{
- struct radix_tree_iter iter;
- void __rcu **slot;
+ XA_STATE(xas, &mapping->i_pages, start);
struct page *page;
unsigned long swapped = 0;
rcu_read_lock();
-
- radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
- if (iter.index >= end)
- break;
-
- page = radix_tree_deref_slot(slot);
-
- if (radix_tree_deref_retry(page)) {
- slot = radix_tree_iter_retry(&iter);
+ xas_for_each(&xas, page, end - 1) {
+ if (xas_retry(&xas, page))
continue;
- }
-
- if (radix_tree_exceptional_entry(page))
+ if (xa_is_value(page))
swapped++;
if (need_resched()) {
- slot = radix_tree_iter_resume(slot, &iter);
+ xas_pause(&xas);
cond_resched_rcu();
}
}
@@ -788,7 +763,7 @@ void shmem_unlock_mapping(struct address_space *mapping)
}
/*
- * Remove range of pages and swap entries from radix tree, and free them.
+ * Remove range of pages and swap entries from page cache, and free them.
* If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate.
*/
static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
@@ -824,7 +799,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
if (index >= end)
break;
- if (radix_tree_exceptional_entry(page)) {
+ if (xa_is_value(page)) {
if (unfalloc)
continue;
nr_swaps_freed += !shmem_free_swap(mapping,
@@ -921,7 +896,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
if (index >= end)
break;
- if (radix_tree_exceptional_entry(page)) {
+ if (xa_is_value(page)) {
if (unfalloc)
continue;
if (shmem_free_swap(mapping, index, page)) {
@@ -1110,34 +1085,27 @@ static void shmem_evict_inode(struct inode *inode)
clear_inode(inode);
}
-static unsigned long find_swap_entry(struct radix_tree_root *root, void *item)
+static unsigned long find_swap_entry(struct xarray *xa, void *item)
{
- struct radix_tree_iter iter;
- void __rcu **slot;
- unsigned long found = -1;
+ XA_STATE(xas, xa, 0);
unsigned int checked = 0;
+ void *entry;
rcu_read_lock();
- radix_tree_for_each_slot(slot, root, &iter, 0) {
- void *entry = radix_tree_deref_slot(slot);
-
- if (radix_tree_deref_retry(entry)) {
- slot = radix_tree_iter_retry(&iter);
+ xas_for_each(&xas, entry, ULONG_MAX) {
+ if (xas_retry(&xas, entry))
continue;
- }
- if (entry == item) {
- found = iter.index;
+ if (entry == item)
break;
- }
checked++;
- if ((checked % 4096) != 0)
+ if ((checked % XA_CHECK_SCHED) != 0)
continue;
- slot = radix_tree_iter_resume(slot, &iter);
+ xas_pause(&xas);
cond_resched_rcu();
}
-
rcu_read_unlock();
- return found;
+
+ return entry ? xas.xa_index : -1;
}
/*
@@ -1175,10 +1143,10 @@ static int shmem_unuse_inode(struct shmem_inode_info *info,
* We needed to drop mutex to make that restrictive page
* allocation, but the inode might have been freed while we
* dropped it: although a racing shmem_evict_inode() cannot
- * complete without emptying the radix_tree, our page lock
+ * complete without emptying the page cache, our page lock
* on this swapcache page is not enough to prevent that -
* free_swap_and_cache() of our swap entry will only
- * trylock_page(), removing swap from radix_tree whatever.
+ * trylock_page(), removing swap from page cache whatever.
*
* We must not proceed to shmem_add_to_page_cache() if the
* inode has been freed, but of course we cannot rely on
@@ -1200,7 +1168,7 @@ static int shmem_unuse_inode(struct shmem_inode_info *info,
*/
if (!error)
error = shmem_add_to_page_cache(*pagep, mapping, index,
- radswap);
+ radswap, gfp);
if (error != -ENOMEM) {
/*
* Truncation and eviction use free_swap_and_cache(), which
@@ -1244,7 +1212,7 @@ int shmem_unuse(swp_entry_t swap, struct page *page)
&memcg, false);
if (error)
goto out;
- /* No radix_tree_preload: swap entry keeps a place for page in tree */
+ /* No memory allocation: swap entry occupies the slot for the page */
error = -EAGAIN;
mutex_lock(&shmem_swaplist_mutex);
@@ -1453,23 +1421,17 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp,
struct shmem_inode_info *info, pgoff_t index)
{
struct vm_area_struct pvma;
- struct inode *inode = &info->vfs_inode;
- struct address_space *mapping = inode->i_mapping;
- pgoff_t idx, hindex;
- void __rcu **results;
+ struct address_space *mapping = info->vfs_inode.i_mapping;
+ pgoff_t hindex;
struct page *page;
if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE))
return NULL;
hindex = round_down(index, HPAGE_PMD_NR);
- rcu_read_lock();
- if (radix_tree_gang_lookup_slot(&mapping->i_pages, &results, &idx,
- hindex, 1) && idx < hindex + HPAGE_PMD_NR) {
- rcu_read_unlock();
+ if (xa_find(&mapping->i_pages, &hindex, hindex + HPAGE_PMD_NR - 1,
+ XA_PRESENT))
return NULL;
- }
- rcu_read_unlock();
shmem_pseudo_vma_init(&pvma, info, hindex);
page = alloc_pages_vma(gfp | __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN,
@@ -1578,8 +1540,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
* a nice clean interface for us to replace oldpage by newpage there.
*/
xa_lock_irq(&swap_mapping->i_pages);
- error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage,
- newpage);
+ error = shmem_replace_entry(swap_mapping, swap_index, oldpage, newpage);
if (!error) {
__inc_node_page_state(newpage, NR_FILE_PAGES);
__dec_node_page_state(oldpage, NR_FILE_PAGES);
@@ -1643,7 +1604,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
repeat:
swap.val = 0;
page = find_lock_entry(mapping, index);
- if (radix_tree_exceptional_entry(page)) {
+ if (xa_is_value(page)) {
swap = radix_to_swp_entry(page);
page = NULL;
}
@@ -1718,7 +1679,7 @@ repeat:
false);
if (!error) {
error = shmem_add_to_page_cache(page, mapping, index,
- swp_to_radix_entry(swap));
+ swp_to_radix_entry(swap), gfp);
/*
* We already confirmed swap under page lock, and make
* no memory allocation here, so usually no possibility
@@ -1824,13 +1785,8 @@ alloc_nohuge: page = shmem_alloc_and_acct_page(gfp, inode,
PageTransHuge(page));
if (error)
goto unacct;
- error = radix_tree_maybe_preload_order(gfp & GFP_RECLAIM_MASK,
- compound_order(page));
- if (!error) {
- error = shmem_add_to_page_cache(page, mapping, hindex,
- NULL);
- radix_tree_preload_end();
- }
+ error = shmem_add_to_page_cache(page, mapping, hindex,
+ NULL, gfp & GFP_RECLAIM_MASK);
if (error) {
mem_cgroup_cancel_charge(page, memcg,
PageTransHuge(page));
@@ -1931,7 +1887,7 @@ unlock:
spin_unlock_irq(&info->lock);
goto repeat;
}
- if (error == -EEXIST) /* from above or from radix_tree_insert */
+ if (error == -EEXIST)
goto repeat;
return error;
}
@@ -2299,11 +2255,8 @@ static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
if (ret)
goto out_release;
- ret = radix_tree_maybe_preload(gfp & GFP_RECLAIM_MASK);
- if (!ret) {
- ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL);
- radix_tree_preload_end();
- }
+ ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL,
+ gfp & GFP_RECLAIM_MASK);
if (ret)
goto out_release_uncharge;
@@ -2548,7 +2501,7 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
}
/*
- * llseek SEEK_DATA or SEEK_HOLE through the radix_tree.
+ * llseek SEEK_DATA or SEEK_HOLE through the page cache.
*/
static pgoff_t shmem_seek_hole_data(struct address_space *mapping,
pgoff_t index, pgoff_t end, int whence)
@@ -2578,7 +2531,7 @@ static pgoff_t shmem_seek_hole_data(struct address_space *mapping,
index = indices[i];
}
page = pvec.pages[i];
- if (page && !radix_tree_exceptional_entry(page)) {
+ if (page && !xa_is_value(page)) {
if (!PageUptodate(page))
page = NULL;
}
diff --git a/mm/swap.c b/mm/swap.c
index 87a54c8dee34..aa483719922e 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -964,7 +964,7 @@ void pagevec_remove_exceptionals(struct pagevec *pvec)
for (i = 0, j = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];
- if (!radix_tree_exceptional_entry(page))
+ if (!xa_is_value(page))
pvec->pages[j++] = page;
}
pvec->nr = j;
@@ -1001,7 +1001,7 @@ EXPORT_SYMBOL(pagevec_lookup_range);
unsigned pagevec_lookup_range_tag(struct pagevec *pvec,
struct address_space *mapping, pgoff_t *index, pgoff_t end,
- int tag)
+ xa_mark_t tag)
{
pvec->nr = find_get_pages_range_tag(mapping, index, end, tag,
PAGEVEC_SIZE, pvec->pages);
@@ -1011,7 +1011,7 @@ EXPORT_SYMBOL(pagevec_lookup_range_tag);
unsigned pagevec_lookup_range_nr_tag(struct pagevec *pvec,
struct address_space *mapping, pgoff_t *index, pgoff_t end,
- int tag, unsigned max_pages)
+ xa_mark_t tag, unsigned max_pages)
{
pvec->nr = find_get_pages_range_tag(mapping, index, end, tag,
min_t(unsigned int, max_pages, PAGEVEC_SIZE), pvec->pages);
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 0d6a7f268d2e..fd2f21e1c60a 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -107,14 +107,15 @@ void show_swap_cache_info(void)
}
/*
- * __add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
+ * add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
* but sets SwapCache flag and private instead of mapping and index.
*/
-int __add_to_swap_cache(struct page *page, swp_entry_t entry)
+int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp)
{
- int error, i, nr = hpage_nr_pages(page);
- struct address_space *address_space;
+ struct address_space *address_space = swap_address_space(entry);
pgoff_t idx = swp_offset(entry);
+ XA_STATE_ORDER(xas, &address_space->i_pages, idx, compound_order(page));
+ unsigned long i, nr = 1UL << compound_order(page);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageSwapCache(page), page);
@@ -123,73 +124,52 @@ int __add_to_swap_cache(struct page *page, swp_entry_t entry)
page_ref_add(page, nr);
SetPageSwapCache(page);
- address_space = swap_address_space(entry);
- xa_lock_irq(&address_space->i_pages);
- for (i = 0; i < nr; i++) {
- set_page_private(page + i, entry.val + i);
- error = radix_tree_insert(&address_space->i_pages,
- idx + i, page + i);
- if (unlikely(error))
- break;
- }
- if (likely(!error)) {
+ do {
+ xas_lock_irq(&xas);
+ xas_create_range(&xas);
+ if (xas_error(&xas))
+ goto unlock;
+ for (i = 0; i < nr; i++) {
+ VM_BUG_ON_PAGE(xas.xa_index != idx + i, page);
+ set_page_private(page + i, entry.val + i);
+ xas_store(&xas, page + i);
+ xas_next(&xas);
+ }
address_space->nrpages += nr;
__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
ADD_CACHE_INFO(add_total, nr);
- } else {
- /*
- * Only the context which have set SWAP_HAS_CACHE flag
- * would call add_to_swap_cache().
- * So add_to_swap_cache() doesn't returns -EEXIST.
- */
- VM_BUG_ON(error == -EEXIST);
- set_page_private(page + i, 0UL);
- while (i--) {
- radix_tree_delete(&address_space->i_pages, idx + i);
- set_page_private(page + i, 0UL);
- }
- ClearPageSwapCache(page);
- page_ref_sub(page, nr);
- }
- xa_unlock_irq(&address_space->i_pages);
+unlock:
+ xas_unlock_irq(&xas);
+ } while (xas_nomem(&xas, gfp));
- return error;
-}
-
-
-int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
-{
- int error;
+ if (!xas_error(&xas))
+ return 0;
- error = radix_tree_maybe_preload_order(gfp_mask, compound_order(page));
- if (!error) {
- error = __add_to_swap_cache(page, entry);
- radix_tree_preload_end();
- }
- return error;
+ ClearPageSwapCache(page);
+ page_ref_sub(page, nr);
+ return xas_error(&xas);
}
/*
* This must be called only on pages that have
* been verified to be in the swap cache.
*/
-void __delete_from_swap_cache(struct page *page)
+void __delete_from_swap_cache(struct page *page, swp_entry_t entry)
{
- struct address_space *address_space;
+ struct address_space *address_space = swap_address_space(entry);
int i, nr = hpage_nr_pages(page);
- swp_entry_t entry;
- pgoff_t idx;
+ pgoff_t idx = swp_offset(entry);
+ XA_STATE(xas, &address_space->i_pages, idx);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageSwapCache(page), page);
VM_BUG_ON_PAGE(PageWriteback(page), page);
- entry.val = page_private(page);
- address_space = swap_address_space(entry);
- idx = swp_offset(entry);
for (i = 0; i < nr; i++) {
- radix_tree_delete(&address_space->i_pages, idx + i);
+ void *entry = xas_store(&xas, NULL);
+ VM_BUG_ON_PAGE(entry != page + i, entry);
set_page_private(page + i, 0);
+ xas_next(&xas);
}
ClearPageSwapCache(page);
address_space->nrpages -= nr;
@@ -217,7 +197,7 @@ int add_to_swap(struct page *page)
return 0;
/*
- * Radix-tree node allocations from PF_MEMALLOC contexts could
+ * XArray node allocations from PF_MEMALLOC contexts could
* completely exhaust the page allocator. __GFP_NOMEMALLOC
* stops emergency reserves from being allocated.
*
@@ -229,7 +209,6 @@ int add_to_swap(struct page *page)
*/
err = add_to_swap_cache(page, entry,
__GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
- /* -ENOMEM radix-tree allocation failure */
if (err)
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely
@@ -263,14 +242,11 @@ fail:
*/
void delete_from_swap_cache(struct page *page)
{
- swp_entry_t entry;
- struct address_space *address_space;
+ swp_entry_t entry = { .val = page_private(page) };
+ struct address_space *address_space = swap_address_space(entry);
- entry.val = page_private(page);
-
- address_space = swap_address_space(entry);
xa_lock_irq(&address_space->i_pages);
- __delete_from_swap_cache(page);
+ __delete_from_swap_cache(page, entry);
xa_unlock_irq(&address_space->i_pages);
put_swap_page(page, entry);
@@ -414,18 +390,10 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
}
/*
- * call radix_tree_preload() while we can wait.
- */
- err = radix_tree_maybe_preload(gfp_mask & GFP_KERNEL);
- if (err)
- break;
-
- /*
* Swap entry may have been freed since our caller observed it.
*/
err = swapcache_prepare(entry);
if (err == -EEXIST) {
- radix_tree_preload_end();
/*
* We might race against get_swap_page() and stumble
* across a SWAP_HAS_CACHE swap_map entry whose page
@@ -433,27 +401,20 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
*/
cond_resched();
continue;
- }
- if (err) { /* swp entry is obsolete ? */
- radix_tree_preload_end();
+ } else if (err) /* swp entry is obsolete ? */
break;
- }
- /* May fail (-ENOMEM) if radix-tree node allocation failed. */
+ /* May fail (-ENOMEM) if XArray node allocation failed. */
__SetPageLocked(new_page);
__SetPageSwapBacked(new_page);
- err = __add_to_swap_cache(new_page, entry);
+ err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL);
if (likely(!err)) {
- radix_tree_preload_end();
- /*
- * Initiate read into locked page and return.
- */
+ /* Initiate read into locked page */
SetPageWorkingset(new_page);
lru_cache_add_anon(new_page);
*new_page_allocated = true;
return new_page;
}
- radix_tree_preload_end();
__ClearPageLocked(new_page);
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely
@@ -626,7 +587,7 @@ int init_swap_address_space(unsigned int type, unsigned long nr_pages)
return -ENOMEM;
for (i = 0; i < nr; i++) {
space = spaces + i;
- INIT_RADIX_TREE(&space->i_pages, GFP_ATOMIC|__GFP_NOWARN);
+ xa_init_flags(&space->i_pages, XA_FLAGS_LOCK_IRQ);
atomic_set(&space->i_mmap_writable, 0);
space->a_ops = &swap_aops;
/* swap cache doesn't use writeback related tags */
diff --git a/mm/truncate.c b/mm/truncate.c
index 1d2fb2dca96f..45d68e90b703 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -33,15 +33,12 @@
static inline void __clear_shadow_entry(struct address_space *mapping,
pgoff_t index, void *entry)
{
- struct radix_tree_node *node;
- void **slot;
+ XA_STATE(xas, &mapping->i_pages, index);
- if (!__radix_tree_lookup(&mapping->i_pages, index, &node, &slot))
+ xas_set_update(&xas, workingset_update_node);
+ if (xas_load(&xas) != entry)
return;
- if (*slot != entry)
- return;
- __radix_tree_replace(&mapping->i_pages, node, slot, NULL,
- workingset_update_node);
+ xas_store(&xas, NULL);
mapping->nrexceptional--;
}
@@ -70,7 +67,7 @@ static void truncate_exceptional_pvec_entries(struct address_space *mapping,
return;
for (j = 0; j < pagevec_count(pvec); j++)
- if (radix_tree_exceptional_entry(pvec->pages[j]))
+ if (xa_is_value(pvec->pages[j]))
break;
if (j == pagevec_count(pvec))
@@ -85,7 +82,7 @@ static void truncate_exceptional_pvec_entries(struct address_space *mapping,
struct page *page = pvec->pages[i];
pgoff_t index = indices[i];
- if (!radix_tree_exceptional_entry(page)) {
+ if (!xa_is_value(page)) {
pvec->pages[j++] = page;
continue;
}
@@ -347,7 +344,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
if (index >= end)
break;
- if (radix_tree_exceptional_entry(page))
+ if (xa_is_value(page))
continue;
if (!trylock_page(page))
@@ -442,7 +439,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
break;
}
- if (radix_tree_exceptional_entry(page))
+ if (xa_is_value(page))
continue;
lock_page(page);
@@ -561,7 +558,7 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
if (index > end)
break;
- if (radix_tree_exceptional_entry(page)) {
+ if (xa_is_value(page)) {
invalidate_exceptional_entry(mapping, index,
page);
continue;
@@ -692,7 +689,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
if (index > end)
break;
- if (radix_tree_exceptional_entry(page)) {
+ if (xa_is_value(page)) {
if (!invalidate_exceptional_entry2(mapping,
index, page))
ret = -EBUSY;
@@ -738,10 +735,10 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
index++;
}
/*
- * For DAX we invalidate page tables after invalidating radix tree. We
+ * For DAX we invalidate page tables after invalidating page cache. We
* could invalidate page tables while invalidating each entry however
* that would be expensive. And doing range unmapping before doesn't
- * work as we have no cheap way to find whether radix tree entry didn't
+ * work as we have no cheap way to find whether page cache entry didn't
* get remapped later.
*/
if (dax_mapping(mapping)) {
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 28c9ae5633b9..62ac0c488624 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -751,12 +751,12 @@ static inline int is_page_cache_freeable(struct page *page)
{
/*
* A freeable page cache page is referenced only by the caller
- * that isolated the page, the page cache radix tree and
- * optional buffer heads at page->private.
+ * that isolated the page, the page cache and optional buffer
+ * heads at page->private.
*/
- int radix_pins = PageTransHuge(page) && PageSwapCache(page) ?
+ int page_cache_pins = PageTransHuge(page) && PageSwapCache(page) ?
HPAGE_PMD_NR : 1;
- return page_count(page) - page_has_private(page) == 1 + radix_pins;
+ return page_count(page) - page_has_private(page) == 1 + page_cache_pins;
}
static int may_write_to_inode(struct inode *inode, struct scan_control *sc)
@@ -932,7 +932,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
if (PageSwapCache(page)) {
swp_entry_t swap = { .val = page_private(page) };
mem_cgroup_swapout(page, swap);
- __delete_from_swap_cache(page);
+ __delete_from_swap_cache(page, swap);
xa_unlock_irqrestore(&mapping->i_pages, flags);
put_swap_page(page, swap);
} else {
diff --git a/mm/workingset.c b/mm/workingset.c
index cbc13d4dfa79..d46f8c92aa2f 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -160,20 +160,20 @@
* and activations is maintained (node->inactive_age).
*
* On eviction, a snapshot of this counter (along with some bits to
- * identify the node) is stored in the now empty page cache radix tree
+ * identify the node) is stored in the now empty page cache
* slot of the evicted page. This is called a shadow entry.
*
* On cache misses for which there are shadow entries, an eligible
* refault distance will immediately activate the refaulting page.
*/
-#define EVICTION_SHIFT (RADIX_TREE_EXCEPTIONAL_ENTRY + \
+#define EVICTION_SHIFT ((BITS_PER_LONG - BITS_PER_XA_VALUE) + \
1 + NODES_SHIFT + MEM_CGROUP_ID_SHIFT)
#define EVICTION_MASK (~0UL >> EVICTION_SHIFT)
/*
* Eviction timestamps need to be able to cover the full range of
- * actionable refaults. However, bits are tight in the radix tree
+ * actionable refaults. However, bits are tight in the xarray
* entry, and after storing the identifier for the lruvec there might
* not be enough left to represent every single actionable refault. In
* that case, we have to sacrifice granularity for distance, and group
@@ -185,22 +185,21 @@ static void *pack_shadow(int memcgid, pg_data_t *pgdat, unsigned long eviction,
bool workingset)
{
eviction >>= bucket_order;
+ eviction &= EVICTION_MASK;
eviction = (eviction << MEM_CGROUP_ID_SHIFT) | memcgid;
eviction = (eviction << NODES_SHIFT) | pgdat->node_id;
eviction = (eviction << 1) | workingset;
- eviction = (eviction << RADIX_TREE_EXCEPTIONAL_SHIFT);
- return (void *)(eviction | RADIX_TREE_EXCEPTIONAL_ENTRY);
+ return xa_mk_value(eviction);
}
static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat,
unsigned long *evictionp, bool *workingsetp)
{
- unsigned long entry = (unsigned long)shadow;
+ unsigned long entry = xa_to_value(shadow);
int memcgid, nid;
bool workingset;
- entry >>= RADIX_TREE_EXCEPTIONAL_SHIFT;
workingset = entry & 1;
entry >>= 1;
nid = entry & ((1UL << NODES_SHIFT) - 1);
@@ -367,7 +366,7 @@ out:
static struct list_lru shadow_nodes;
-void workingset_update_node(struct radix_tree_node *node)
+void workingset_update_node(struct xa_node *node)
{
/*
* Track non-empty nodes that contain only shadow entries;
@@ -379,7 +378,7 @@ void workingset_update_node(struct radix_tree_node *node)
*/
VM_WARN_ON_ONCE(!irqs_disabled()); /* For __inc_lruvec_page_state */
- if (node->count && node->count == node->exceptional) {
+ if (node->count && node->count == node->nr_values) {
if (list_empty(&node->private_list)) {
list_lru_add(&shadow_nodes, &node->private_list);
__inc_lruvec_page_state(virt_to_page(node),
@@ -404,7 +403,7 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
nodes = list_lru_shrink_count(&shadow_nodes, sc);
/*
- * Approximate a reasonable limit for the radix tree nodes
+ * Approximate a reasonable limit for the nodes
* containing shadow entries. We don't need to keep more
* shadow entries than possible pages on the active list,
* since refault distances bigger than that are dismissed.
@@ -419,11 +418,11 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
* worst-case density of 1/8th. Below that, not all eligible
* refaults can be detected anymore.
*
- * On 64-bit with 7 radix_tree_nodes per page and 64 slots
+ * On 64-bit with 7 xa_nodes per page and 64 slots
* each, this will reclaim shadow entries when they consume
* ~1.8% of available memory:
*
- * PAGE_SIZE / radix_tree_nodes / node_entries * 8 / PAGE_SIZE
+ * PAGE_SIZE / xa_nodes / node_entries * 8 / PAGE_SIZE
*/
#ifdef CONFIG_MEMCG
if (sc->memcg) {
@@ -438,7 +437,7 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
#endif
pages = node_present_pages(sc->nid);
- max_nodes = pages >> (RADIX_TREE_MAP_SHIFT - 3);
+ max_nodes = pages >> (XA_CHUNK_SHIFT - 3);
if (!nodes)
return SHRINK_EMPTY;
@@ -451,11 +450,11 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
static enum lru_status shadow_lru_isolate(struct list_head *item,
struct list_lru_one *lru,
spinlock_t *lru_lock,
- void *arg)
+ void *arg) __must_hold(lru_lock)
{
+ struct xa_node *node = container_of(item, struct xa_node, private_list);
+ XA_STATE(xas, node->array, 0);
struct address_space *mapping;
- struct radix_tree_node *node;
- unsigned int i;
int ret;
/*
@@ -463,15 +462,14 @@ static enum lru_status shadow_lru_isolate(struct list_head *item,
* the shadow node LRU under the i_pages lock and the
* lru_lock. Because the page cache tree is emptied before
* the inode can be destroyed, holding the lru_lock pins any
- * address_space that has radix tree nodes on the LRU.
+ * address_space that has nodes on the LRU.
*
* We can then safely transition to the i_pages lock to
* pin only the address_space of the particular node we want
* to reclaim, take the node off-LRU, and drop the lru_lock.
*/
- node = container_of(item, struct radix_tree_node, private_list);
- mapping = container_of(node->root, struct address_space, i_pages);
+ mapping = container_of(node->array, struct address_space, i_pages);
/* Coming from the list, invert the lock order */
if (!xa_trylock(&mapping->i_pages)) {
@@ -490,29 +488,21 @@ static enum lru_status shadow_lru_isolate(struct list_head *item,
* no pages, so we expect to be able to remove them all and
* delete and free the empty node afterwards.
*/
- if (WARN_ON_ONCE(!node->exceptional))
+ if (WARN_ON_ONCE(!node->nr_values))
goto out_invalid;
- if (WARN_ON_ONCE(node->count != node->exceptional))
- goto out_invalid;
- for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) {
- if (node->slots[i]) {
- if (WARN_ON_ONCE(!radix_tree_exceptional_entry(node->slots[i])))
- goto out_invalid;
- if (WARN_ON_ONCE(!node->exceptional))
- goto out_invalid;
- if (WARN_ON_ONCE(!mapping->nrexceptional))
- goto out_invalid;
- node->slots[i] = NULL;
- node->exceptional--;
- node->count--;
- mapping->nrexceptional--;
- }
- }
- if (WARN_ON_ONCE(node->exceptional))
+ if (WARN_ON_ONCE(node->count != node->nr_values))
goto out_invalid;
+ mapping->nrexceptional -= node->nr_values;
+ xas.xa_node = xa_parent_locked(&mapping->i_pages, node);
+ xas.xa_offset = node->offset;
+ xas.xa_shift = node->shift + XA_CHUNK_SHIFT;
+ xas_set_update(&xas, workingset_update_node);
+ /*
+ * We could store a shadow entry here which was the minimum of the
+ * shadow entries we were tracking ...
+ */
+ xas_store(&xas, NULL);
__inc_lruvec_page_state(virt_to_page(node), WORKINGSET_NODERECLAIM);
- __radix_tree_delete_node(&mapping->i_pages, node,
- workingset_lookup_update(mapping));
out_invalid:
xa_unlock_irq(&mapping->i_pages);
generated by cgit (git 2.34.1) at 2024-05-17 18:28:59 +0000