Instead of a 'goto restart', we can now use radix_tree_iter_retry() to
restart from our current position. This will make a difference when
there are more ways to happen across an indirect pointer. And it
eliminates some confusing gotos.
[vbabka@suse.cz: remove now-obsolete-and-misleading comment]
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
return 0;
rcu_read_lock();
return 0;
rcu_read_lock();
radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
struct page *page;
repeat:
radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
struct page *page;
repeat:
if (unlikely(!page))
continue;
if (radix_tree_exception(page)) {
if (unlikely(!page))
continue;
if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page))
- goto restart;
+ 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
/*
* A shadow entry of a recently evicted page, a swap
* entry from shmem/tmpfs or a DAX entry. Return it
return 0;
rcu_read_lock();
return 0;
rcu_read_lock();
radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
struct page *page;
repeat:
radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
struct page *page;
repeat:
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
- /*
- * Transient condition which can only trigger
- * when entry at index 0 moves out of or back
- * to root: none yet gotten, safe to restart.
- */
- WARN_ON(iter.index);
- goto restart;
+ slot = radix_tree_iter_retry(&iter);
+ continue;
}
/*
* A shadow entry of a recently evicted page,
}
/*
* A shadow entry of a recently evicted page,
return 0;
rcu_read_lock();
return 0;
rcu_read_lock();
radix_tree_for_each_contig(slot, &mapping->page_tree, &iter, index) {
struct page *page;
repeat:
radix_tree_for_each_contig(slot, &mapping->page_tree, &iter, index) {
struct page *page;
repeat:
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
- /*
- * Transient condition which can only trigger
- * when entry at index 0 moves out of or back
- * to root: none yet gotten, safe to restart.
- */
- goto restart;
+ slot = radix_tree_iter_retry(&iter);
+ continue;
}
/*
* A shadow entry of a recently evicted page,
}
/*
* A shadow entry of a recently evicted page,
return 0;
rcu_read_lock();
return 0;
rcu_read_lock();
radix_tree_for_each_tagged(slot, &mapping->page_tree,
&iter, *index, tag) {
struct page *page;
radix_tree_for_each_tagged(slot, &mapping->page_tree,
&iter, *index, tag) {
struct page *page;
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
- /*
- * Transient condition which can only trigger
- * when entry at index 0 moves out of or back
- * to root: none yet gotten, safe to restart.
- */
- goto restart;
+ slot = radix_tree_iter_retry(&iter);
+ continue;
}
/*
* A shadow entry of a recently evicted page.
}
/*
* A shadow entry of a recently evicted page.
return 0;
rcu_read_lock();
return 0;
rcu_read_lock();
radix_tree_for_each_tagged(slot, &mapping->page_tree,
&iter, start, tag) {
struct page *page;
radix_tree_for_each_tagged(slot, &mapping->page_tree,
&iter, start, tag) {
struct page *page;
continue;
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
continue;
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
- /*
- * Transient condition which can only trigger
- * when entry at index 0 moves out of or back
- * to root: none yet gotten, safe to restart.
- */
- goto restart;
+ slot = radix_tree_iter_retry(&iter);
+ continue;
if (unlikely(!page))
goto next;
if (radix_tree_exception(page)) {
if (unlikely(!page))
goto next;
if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page))
- break;
- else
- goto next;
+ if (radix_tree_deref_retry(page)) {
+ slot = radix_tree_iter_retry(&iter);
+ continue;
+ }
+ goto next;
}
if (!page_cache_get_speculative(page))
}
if (!page_cache_get_speculative(page))
page = radix_tree_deref_slot(slot);
page = radix_tree_deref_slot(slot);
- /*
- * This should only be possible to happen at index 0, so we
- * don't need to reset the counter, nor do we risk infinite
- * restarts.
- */
- if (radix_tree_deref_retry(page))
- goto restart;
+ if (radix_tree_deref_retry(page)) {
+ slot = radix_tree_iter_retry(&iter);
+ continue;
+ }
if (radix_tree_exceptional_entry(page))
swapped++;
if (radix_tree_exceptional_entry(page))
swapped++;
radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
page = radix_tree_deref_slot(slot);
if (!page || radix_tree_exception(page)) {
radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
page = radix_tree_deref_slot(slot);
if (!page || radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page))
- goto restart;
+ if (radix_tree_deref_retry(page)) {
+ slot = radix_tree_iter_retry(&iter);
+ continue;
+ }
} else if (page_count(page) - page_mapcount(page) > 1) {
spin_lock_irq(&mapping->tree_lock);
radix_tree_tag_set(&mapping->page_tree, iter.index,
} else if (page_count(page) - page_mapcount(page) > 1) {
spin_lock_irq(&mapping->tree_lock);
radix_tree_tag_set(&mapping->page_tree, iter.index,
page = radix_tree_deref_slot(slot);
if (radix_tree_exception(page)) {
page = radix_tree_deref_slot(slot);
if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page))
- goto restart;
+ if (radix_tree_deref_retry(page)) {
+ slot = radix_tree_iter_retry(&iter);
+ continue;
+ }